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      9 <h1 align="center">The XML C parser and toolkit of Gnome</h1>
     10 
     11 <h1>Note: this is the flat content of the <a href="index.html">web
     12 site</a></h1>
     13 
     14 <h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1>
     15 
     16 <p></p>
     17 
     18 <p
     19 style="text-align: right; font-style: italic; font-size: 10pt">"Programming
     20 with libxml2 is like the thrilling embrace of an exotic stranger." <a
     21 href="http://diveintomark.org/archives/2004/02/18/libxml2">Mark
     22 Pilgrim</a></p>
     23 
     24 <p>Libxml2 is the XML C parser and toolkit developed for the Gnome project
     25 (but usable outside of the Gnome platform), it is free software available
     26 under the <a href="http://www.opensource.org/licenses/mit-license.html">MIT
     27 License</a>. XML itself is a metalanguage to design markup languages, i.e.
     28 text language where semantic and structure are added to the content using
     29 extra "markup" information enclosed between angle brackets. HTML is the most
     30 well-known markup language. Though the library is written in C <a
     31 href="python.html">a variety of language bindings</a> make it available in
     32 other environments.</p>
     33 
     34 <p>Libxml2 is known to be very portable, the library should build and work
     35 without serious troubles on a variety of systems (Linux, Unix, Windows,
     36 CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, VxWorks, ...)</p>
     37 
     38 <p>Libxml2 implements a number of existing standards related to markup
     39 languages:</p>
     40 <ul>
     41   <li>the XML standard: <a
     42     href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li>
     43   <li>Namespaces in XML: <a
     44     href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li>
     45   <li>XML Base: <a
     46     href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li>
     47   <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> :
     48     Uniform Resource Identifiers <a
     49     href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li>
     50   <li>XML Path Language (XPath) 1.0: <a
     51     href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li>
     52   <li>HTML4 parser: <a
     53     href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li>
     54   <li>XML Pointer Language (XPointer) Version 1.0: <a
     55     href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li>
     56   <li>XML Inclusions (XInclude) Version 1.0: <a
     57     href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li>
     58   <li>ISO-8859-x encodings, as well as <a
     59     href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8]
     60     and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a>
     61     [UTF-16] Unicode encodings, and more if using iconv support</li>
     62   <li>part of SGML Open Technical Resolution TR9401:1997</li>
     63   <li>XML Catalogs Working Draft 06 August 2001: <a
     64     href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li>
     65   <li>Canonical XML Version 1.0: <a
     66     href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a>
     67     and the Exclusive XML Canonicalization CR draft <a
     68     href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li>
     69   <li>Relax NG, ISO/IEC 19757-2:2003, <a
     70     href="http://www.oasis-open.org/committees/relax-ng/spec-20011203.html">http://www.oasis-open.org/committees/relax-ng/spec-20011203.html</a></li>
     71   <li>W3C XML Schemas Part 2: Datatypes <a
     72     href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/">REC 02 May
     73     2001</a></li>
     74   <li>W3C <a href="http://www.w3.org/TR/xml-id/">xml:id</a> Working Draft 7
     75     April 2004</li>
     76 </ul>
     77 
     78 <p>In most cases libxml2 tries to implement the specifications in a
     79 relatively strictly compliant way. As of release 2.4.16, libxml2 passed all
     80 1800+ tests from the <a
     81 href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests
     82 Suite</a>.</p>
     83 
     84 <p>To some extent libxml2 provides support for the following additional
     85 specifications but doesn't claim to implement them completely:</p>
     86 <ul>
     87   <li>Document Object Model (DOM) <a
     88     href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a>
     89     the document model, but it doesn't implement the API itself, gdome2 does
     90     this on top of libxml2</li>
     91   <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> :
     92     libxml2 implements a basic FTP client code</li>
     93   <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> :
     94     HTTP/1.0, again a basic HTTP client code</li>
     95   <li>SAX: a SAX2 like interface and a minimal SAX1 implementation compatible
     96     with early expat versions</li>
     97 </ul>
     98 
     99 <p>A partial implementation of <a
    100 href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/">XML Schemas Part
    101 1: Structure</a> is being worked on but it would be far too early to make any
    102 conformance statement about it at the moment.</p>
    103 
    104 <p>Separate documents:</p>
    105 <ul>
    106   <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an
    107     implementation of XSLT 1.0 and common extensions like EXSLT for
    108   libxml2</li>
    109   <li><a href="http://gdome2.cs.unibo.it/">the gdome2 page</a>
    110     : a standard DOM2 implementation for libxml2</li>
    111   <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an
    112     implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML
    113     Digital Signature</a> for libxml2</li>
    114   <li>also check the related links section for more related and active
    115     projects.</li>
    116 </ul>
    117 <p> Hosting sponsored by <a href="http://www.aoemedia.de/opensource-cms.html"
    118 >Open Source CMS services</a> from AOE media.</p>
    119 
    120 <p>Logo designed by <a href="mailto:liyanage (a] access.ch">Marc Liyanage</a>.</p>
    121 
    122 <h2><a name="Introducti">Introduction</a></h2>
    123 
    124 <p>This document describes libxml, the <a
    125 href="http://www.w3.org/XML/">XML</a> C parser and toolkit developed for the
    126 <a href="http://www.gnome.org/">Gnome</a> project. <a
    127 href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based
    128 structured documents/data.</p>
    129 
    130 <p>Here are some key points about libxml:</p>
    131 <ul>
    132   <li>Libxml2 exports Push (progressive) and Pull (blocking) type parser
    133     interfaces for both XML and HTML.</li>
    134   <li>Libxml2 can do DTD validation at parse time, using a parsed document
    135     instance, or with an arbitrary DTD.</li>
    136   <li>Libxml2 includes complete <a
    137     href="http://www.w3.org/TR/xpath">XPath</a>, <a
    138     href="http://www.w3.org/TR/xptr">XPointer</a> and <a
    139     href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li>
    140   <li>It is written in plain C, making as few assumptions as possible, and
    141     sticking closely to ANSI C/POSIX for easy embedding. Works on
    142     Linux/Unix/Windows, ported to a number of other platforms.</li>
    143   <li>Basic support for HTTP and FTP client allowing applications to fetch
    144     remote resources.</li>
    145   <li>The design is modular, most of the extensions can be compiled out.</li>
    146   <li>The internal document representation is as close as possible to the <a
    147     href="http://www.w3.org/DOM/">DOM</a> interfaces.</li>
    148   <li>Libxml2 also has a <a
    149     href="http://www.megginson.com/SAX/index.html">SAX like interface</a>;
    150     the interface is designed to be compatible with <a
    151     href="http://www.jclark.com/xml/expat.html">Expat</a>.</li>
    152   <li>This library is released under the <a
    153     href="http://www.opensource.org/licenses/mit-license.html">MIT
    154     License</a>. See the Copyright file in the distribution for the precise
    155     wording.</li>
    156 </ul>
    157 
    158 <p>Warning: unless you are forced to because your application links with a
    159 Gnome-1.X library requiring it,  <strong><span
    160 style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use
    161 libxml2</p>
    162 
    163 <h2><a name="FAQ">FAQ</a></h2>
    164 
    165 <p>Table of Contents:</p>
    166 <ul>
    167   <li><a href="FAQ.html#License">License(s)</a></li>
    168   <li><a href="FAQ.html#Installati">Installation</a></li>
    169   <li><a href="FAQ.html#Compilatio">Compilation</a></li>
    170   <li><a href="FAQ.html#Developer">Developer corner</a></li>
    171 </ul>
    172 
    173 <h3><a name="License">License</a>(s)</h3>
    174 <ol>
    175   <li><em>Licensing Terms for libxml</em>
    176     <p>libxml2 is released under the <a
    177     href="http://www.opensource.org/licenses/mit-license.html">MIT
    178     License</a>; see the file Copyright in the distribution for the precise
    179     wording</p>
    180   </li>
    181   <li><em>Can I embed libxml2 in a proprietary application ?</em>
    182     <p>Yes. The MIT License allows you to keep proprietary the changes you
    183     made to libxml, but it would be graceful to send-back bug fixes and
    184     improvements as patches for possible incorporation in the main
    185     development tree.</p>
    186   </li>
    187 </ol>
    188 
    189 <h3><a name="Installati">Installation</a></h3>
    190 <ol>
    191   <li><strong><span style="background-color: #FF0000">Do Not Use
    192     libxml1</span></strong>, use libxml2</li>
    193   <p></p>
    194   <li><em>Where can I get libxml</em> ?
    195     <p>The original distribution comes from <a
    196     href="ftp://xmlsoft.org/libxml2/">xmlsoft.org</a> or <a
    197     href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.6/">gnome.org</a></p>
    198     <p>Most Linux and BSD distributions include libxml, this is probably the
    199     safer way for end-users to use libxml.</p>
    200     <p>David Doolin provides precompiled Windows versions at <a
    201     href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/         ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p>
    202   </li>
    203   <p></p>
    204   <li><em>I see libxml and libxml2 releases, which one should I install ?</em>
    205     <ul>
    206       <li>If you are not constrained by backward compatibility issues with
    207         existing applications, install libxml2 only</li>
    208       <li>If you are not doing development, you can safely install both.
    209         Usually the packages <a
    210         href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a
    211         href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are
    212         compatible (this is not the case for development packages).</li>
    213       <li>If you are a developer and your system provides separate packaging
    214         for shared libraries and the development components, it is possible
    215         to install libxml and libxml2, and also <a
    216         href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a>
    217         and <a
    218         href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>
    219         too for libxml2 &gt;= 2.3.0</li>
    220       <li>If you are developing a new application, please develop against
    221         libxml2(-devel)</li>
    222     </ul>
    223   </li>
    224   <li><em>I can't install the libxml package, it conflicts with libxml0</em>
    225     <p>You probably have an old libxml0 package used to provide the shared
    226     library for libxml.so.0, you can probably safely remove it. The libxml
    227     packages provided on <a
    228     href="ftp://xmlsoft.org/libxml2/">xmlsoft.org</a> provide
    229     libxml.so.0</p>
    230   </li>
    231   <li><em>I can't install the libxml(2) RPM package due to failed
    232     dependencies</em>
    233     <p>The most generic solution is to re-fetch the latest src.rpm , and
    234     rebuild it locally with</p>
    235     <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p>
    236     <p>If everything goes well it will generate two binary rpm packages (one
    237     providing the shared libs and xmllint, and the other one, the -devel
    238     package, providing includes, static libraries and scripts needed to build
    239     applications with libxml(2)) that you can install locally.</p>
    240   </li>
    241 </ol>
    242 
    243 <h3><a name="Compilatio">Compilation</a></h3>
    244 <ol>
    245   <li><em>What is the process to compile libxml2 ?</em>
    246     <p>As most UNIX libraries libxml2 follows the "standard":</p>
    247     <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p>
    248     <p><code>cd libxml-xxxx</code></p>
    249     <p><code>./configure --help</code></p>
    250     <p>to see the options, then the compilation/installation proper</p>
    251     <p><code>./configure [possible options]</code></p>
    252     <p><code>make</code></p>
    253     <p><code>make install</code></p>
    254     <p>At that point you may have to rerun ldconfig or a similar utility to
    255     update your list of installed shared libs.</p>
    256   </li>
    257   <li><em>What other libraries are needed to compile/install libxml2 ?</em>
    258     <p>Libxml2 does not require any other library, the normal C ANSI API
    259     should be sufficient (please report any violation to this rule you may
    260     find).</p>
    261     <p>However if found at configuration time libxml2 will detect and use the
    262     following libs:</p>
    263     <ul>
    264       <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a
    265         highly portable and available widely compression library.</li>
    266       <li>iconv: a powerful character encoding conversion library. It is
    267         included by default in recent glibc libraries, so it doesn't need to
    268         be installed specifically on Linux. It now seems a <a
    269         href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part
    270         of the official UNIX</a> specification. Here is one <a
    271         href="http://www.gnu.org/software/libiconv/">implementation of the
    272         library</a> which source can be found <a
    273         href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li>
    274     </ul>
    275   </li>
    276   <p></p>
    277   <li><em>Make check fails on some platforms</em>
    278     <p>Sometimes the regression tests' results don't completely match the
    279     value produced by the parser, and the makefile uses diff to print the
    280     delta. On some platforms the diff return breaks the compilation process;
    281     if the diff is small this is probably not a serious problem.</p>
    282     <p>Sometimes (especially on Solaris) make checks fail due to limitations
    283     in make. Try using GNU-make instead.</p>
    284   </li>
    285   <li><em>I use the SVN version and there is no configure script</em>
    286     <p>The configure script (and other Makefiles) are generated. Use the
    287     autogen.sh script to regenerate the configure script and Makefiles,
    288     like:</p>
    289     <p><code>./autogen.sh --prefix=/usr --disable-shared</code></p>
    290   </li>
    291   <li><em>I have troubles when running make tests with gcc-3.0</em>
    292     <p>It seems the initial release of gcc-3.0 has a problem with the
    293     optimizer which miscompiles the URI module. Please use another
    294     compiler.</p>
    295   </li>
    296 </ol>
    297 
    298 <h3><a name="Developer">Developer</a> corner</h3>
    299 <ol>
    300   <li><em>Troubles compiling or linking programs using libxml2</em>
    301     <p>Usually the problem comes from the fact that the compiler doesn't get
    302     the right compilation or linking flags. There is a small shell script
    303     <code>xml2-config</code> which is installed as part of libxml2 usual
    304     install process which provides those flags. Use</p>
    305     <p><code>xml2-config --cflags</code></p>
    306     <p>to get the compilation flags and</p>
    307     <p><code>xml2-config --libs</code></p>
    308     <p>to get the linker flags. Usually this is done directly from the
    309     Makefile as:</p>
    310     <p><code>CFLAGS=`xml2-config --cflags`</code></p>
    311     <p><code>LIBS=`xml2-config --libs`</code></p>
    312   </li>
    313   <li><em>I want to install my own copy of libxml2 in my home directory and
    314     link my programs against it, but it doesn't work</em>
    315     <p>There are many different ways to accomplish this.  Here is one way to
    316     do this under Linux.  Suppose your home directory is <code>/home/user.
    317     </code>Then:</p>
    318     <ul>
    319       <li>Create a subdirectory, let's call it <code>myxml</code></li>
    320       <li>unpack the libxml2 distribution into that subdirectory</li>
    321       <li>chdir into the unpacked distribution
    322         (<code>/home/user/myxml/libxml2 </code>)</li>
    323       <li>configure the library using the "<code>--prefix</code>" switch,
    324         specifying an installation subdirectory in
    325         <code>/home/user/myxml</code>, e.g.
    326         <p><code>./configure --prefix /home/user/myxml/xmlinst</code> {other
    327         configuration options}</p>
    328       </li>
    329       <li>now run <code>make</code> followed by <code>make install</code></li>
    330       <li>At this point, the installation subdirectory contains the complete
    331         "private" include files, library files and binary program files (e.g.
    332         xmllint), located in
    333         <p><code>/home/user/myxml/xmlinst/lib,
    334         /home/user/myxml/xmlinst/include </code> and <code>
    335         /home/user/myxml/xmlinst/bin</code></p>
    336         respectively.</li>
    337       <li>In order to use this "private" library, you should first add it to
    338         the beginning of your default PATH (so that your own private program
    339         files such as xmllint will be used instead of the normal system
    340         ones).  To do this, the Bash command would be
    341         <p><code>export PATH=/home/user/myxml/xmlinst/bin:$PATH</code></p>
    342       </li>
    343       <li>Now suppose you have a program <code>test1.c</code> that you would
    344         like to compile with your "private" library.  Simply compile it using
    345         the command
    346         <p><code>gcc `xml2-config --cflags --libs` -o test test.c</code></p>
    347         Note that, because your PATH has been set with <code>
    348         /home/user/myxml/xmlinst/bin</code> at the beginning, the xml2-config
    349         program which you just installed will be used instead of the system
    350         default one, and this will <em>automatically</em> get the correct
    351         libraries linked with your program.</li>
    352     </ul>
    353   </li>
    354 
    355   <p></p>
    356   <li><em>xmlDocDump() generates output on one line.</em>
    357     <p>Libxml2 will not <strong>invent</strong> spaces in the content of a
    358     document since <strong>all spaces in the content of a document are
    359     significant</strong>. If you build a tree from the API and want
    360     indentation:</p>
    361     <ol>
    362       <li>the correct way is to generate those yourself too.</li>
    363       <li>the dangerous way is to ask libxml2 to add those blanks to your
    364         content <strong>modifying the content of your document in the
    365         process</strong>. The result may not be what you expect. There is
    366         <strong>NO</strong> way to guarantee that such a modification won't
    367         affect other parts of the content of your document. See <a
    368         href="http://xmlsoft.org/html/libxml-parser.html#xmlKeepBlanksDefault">xmlKeepBlanksDefault
    369         ()</a> and <a
    370         href="http://xmlsoft.org/html/libxml-tree.html#xmlSaveFormatFile">xmlSaveFormatFile
    371         ()</a></li>
    372     </ol>
    373   </li>
    374   <p></p>
    375   <li><em>Extra nodes in the document:</em>
    376     <p><em>For an XML file as below:</em></p>
    377     <pre>&lt;?xml version="1.0"?&gt;
    378 &lt;PLAN xmlns="http://www.argus.ca/autotest/1.0/"&gt;
    379 &lt;NODE CommFlag="0"/&gt;
    380 &lt;NODE CommFlag="1"/&gt;
    381 &lt;/PLAN&gt;</pre>
    382     <p><em>after parsing it with the function
    383     pxmlDoc=xmlParseFile(...);</em></p>
    384     <p><em>I want to the get the content of the first node (node with the
    385     CommFlag="0")</em></p>
    386     <p><em>so I did it as following;</em></p>
    387     <pre>xmlNodePtr pnode;
    388 pnode=pxmlDoc-&gt;children-&gt;children;</pre>
    389     <p><em>but it does not work. If I change it to</em></p>
    390     <pre>pnode=pxmlDoc-&gt;children-&gt;children-&gt;next;</pre>
    391     <p><em>then it works.  Can someone explain it to me.</em></p>
    392     <p></p>
    393     <p>In XML all characters in the content of the document are significant
    394     <strong>including blanks and formatting line breaks</strong>.</p>
    395     <p>The extra nodes you are wondering about are just that, text nodes with
    396     the formatting spaces which are part of the document but that people tend
    397     to forget. There is a function <a
    398     href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault
    399     ()</a>  to remove those at parse time, but that's an heuristic, and its
    400     use should be limited to cases where you are certain there is no
    401     mixed-content in the document.</p>
    402   </li>
    403   <li><em>I get compilation errors of existing code like when accessing
    404     <strong>root</strong> or <strong>child fields</strong> of nodes.</em>
    405     <p>You are compiling code developed for libxml version 1 and using a
    406     libxml2 development environment. Either switch back to libxml v1 devel or
    407     even better fix the code to compile with libxml2 (or both) by <a
    408     href="upgrade.html">following the instructions</a>.</p>
    409   </li>
    410   <li><em>I get compilation errors about non existing
    411     <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong>
    412     fields.</em>
    413     <p>The source code you are using has been <a
    414     href="upgrade.html">upgraded</a> to be able to compile with both libxml
    415     and libxml2, but you need to install a more recent version:
    416     libxml(-devel) &gt;= 1.8.8 or libxml2(-devel) &gt;= 2.1.0</p>
    417   </li>
    418   <li><em>Random crashes in threaded applications</em>
    419     <p>Read and follow all advices on the <a href="threads.html">thread
    420     safety</a> page, and make 100% sure you never call xmlCleanupParser()
    421     while the library or an XML document might still be in use by another
    422     thread.</p>
    423   </li>
    424   <li><em>The example provided in the web page does not compile.</em>
    425     <p>It's hard to maintain the documentation in sync with the code
    426     &lt;grin/&gt; ...</p>
    427     <p>Check the previous points 1/ and 2/ raised before, and please send
    428     patches.</p>
    429   </li>
    430   <li><em>Where can I get more examples and information than provided on the
    431     web page?</em>
    432     <p>Ideally a libxml2 book would be nice. I have no such plan ... But you
    433     can:</p>
    434     <ul>
    435       <li>check more deeply the <a href="html/libxml-lib.html">existing
    436         generated doc</a></li>
    437       <li>have a look at <a href="examples/index.html">the set of
    438         examples</a>.</li>
    439       <li>look for examples of use for libxml2 function using the Gnome code
    440           or by asking on Google.</li>
    441       <li><a
    442         href="http://svn.gnome.org/viewvc/libxml2/trunk/">Browse
    443         the libxml2 source</a> , I try to write code as clean and documented
    444         as possible, so looking at it may be helpful. In particular the code
    445         of <a href="http://svn.gnome.org/viewvc/libxml2/trunk/xmllint.c?view=markup">xmllint.c</a> and of the various testXXX.c test programs should
    446         provide good examples of how to do things with the library.</li>
    447     </ul>
    448   </li>
    449   <p></p>
    450   <li><em>What about C++ ?</em>
    451     <p>libxml2 is written in pure C in order to allow easy reuse on a number
    452     of platforms, including embedded systems. I don't intend to convert to
    453     C++.</p>
    454     <p>There is however a C++ wrapper which may fulfill your needs:</p>
    455     <ul>
    456       <li>by Ari Johnson &lt;ari (a] btigate.com&gt;:
    457         <p>Website: <a
    458         href="http://libxmlplusplus.sourceforge.net/">http://libxmlplusplus.sourceforge.net/</a></p>
    459         <p>Download: <a
    460         href="http://sourceforge.net/project/showfiles.php?group_id=12999">http://sourceforge.net/project/showfiles.php?group_id=12999</a></p>
    461       </li>
    462     </ul>
    463   </li>
    464   <li><em>How to validate a document a posteriori ?</em>
    465     <p>It is possible to validate documents which had not been validated at
    466     initial parsing time or documents which have been built from scratch
    467     using the API. Use the <a
    468     href="http://xmlsoft.org/html/libxml-valid.html#xmlValidateDtd">xmlValidateDtd()</a>
    469     function. It is also possible to simply add a DTD to an existing
    470     document:</p>
    471     <pre>xmlDocPtr doc; /* your existing document */
    472 xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */
    473 
    474         dtd-&gt;name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */
    475 
    476         doc-&gt;intSubset = dtd;
    477         if (doc-&gt;children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd);
    478         else xmlAddPrevSibling(doc-&gt;children, (xmlNodePtr)dtd);
    479           </pre>
    480   </li>
    481   <li><em>So what is this funky "xmlChar" used all the time?</em>
    482     <p>It is a null terminated sequence of utf-8 characters. And only utf-8!
    483     You need to convert strings encoded in different ways to utf-8 before
    484     passing them to the API.  This can be accomplished with the iconv library
    485     for instance.</p>
    486   </li>
    487   <li>etc ...</li>
    488 </ol>
    489 
    490 <p></p>
    491 
    492 <h2><a name="Documentat">Developer Menu</a></h2>
    493 
    494 <p>There are several on-line resources related to using libxml:</p>
    495 <ol>
    496   <li>Use the <a href="search.php">search engine</a> to look up
    497   information.</li>
    498   <li>Check the <a href="FAQ.html">FAQ.</a></li>
    499   <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive
    500     documentation</a> automatically extracted from code comments.</li>
    501   <li>Look at the documentation about <a href="encoding.html">libxml
    502     internationalization support</a>.</li>
    503   <li>This page provides a global overview and <a href="example.html">some
    504     examples</a> on how to use libxml.</li>
    505   <li><a href="examples/index.html">Code examples</a></li>
    506   <li>John Fleck's libxml2 tutorial: <a href="tutorial/index.html">html</a>
    507     or <a href="tutorial/xmltutorial.pdf">pdf</a>.</li>
    508   <li>If you need to parse large files, check the <a
    509     href="xmlreader.html">xmlReader</a> API tutorial</li>
    510   <li><a href="mailto:james (a] daa.com.au">James Henstridge</a> wrote <a
    511     href="http://www.jamesh.id.au/articles/libxml-sax/libxml-sax.html">some nice
    512     documentation</a> explaining how to use the libxml SAX interface.</li>
    513   <li>George Lebl wrote <a
    514     href="http://www-106.ibm.com/developerworks/library/l-gnome3/">an article
    515     for IBM developerWorks</a> about using libxml.</li>
    516   <li>Check <a href="http://svn.gnome.org/viewvc/libxml2/trunk/TODO?view=markup">the TODO
    517     file</a>.</li>
    518   <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a>
    519     description. If you are starting a new project using libxml you should
    520     really use the 2.x version.</li>
    521   <li>And don't forget to look at the <a
    522     href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li>
    523 </ol>
    524 
    525 <h2><a name="Reporting">Reporting bugs and getting help</a></h2>
    526 
    527 <p>Well, bugs or missing features are always possible, and I will make a
    528 point of fixing them in a timely fashion. The best way to report a bug is to
    529 use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Gnome
    530 bug tracking database</a> (make sure to use the "libxml2" module name). I
    531 look at reports there regularly and it's good to have a reminder when a bug
    532 is still open. Be sure to specify that the bug is for the package libxml2.</p>
    533 
    534 <p>For small problems you can try to get help on IRC, the #xml channel on
    535 irc.gnome.org (port 6667) usually have a few person subscribed which may help
    536 (but there is no guarantee and if a real issue is raised it should go on the
    537 mailing-list for archival).</p>
    538 
    539 <p>There is also a mailing-list <a
    540 href="mailto:xml (a] gnome.org">xml (a] gnome.org</a> for libxml, with an  <a
    541 href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a
    542 href="http://xmlsoft.org/messages">old</a>). To subscribe to this list,
    543 please visit the <a
    544 href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and
    545 follow the instructions. <strong>Do not send code, I won't debug it</strong>
    546 (but patches are really appreciated!).</p>
    547 
    548 <p>Please note that with the current amount of virus and SPAM, sending mail
    549 to the list without being subscribed won't work. There is *far too many
    550 bounces* (in the order of a thousand a day !) I cannot approve them manually
    551 anymore. If your mail to the list bounced waiting for administrator approval,
    552 it is LOST ! Repost it and fix the problem triggering the error. Also please
    553 note that <span style="color: #FF0000; background-color: #FFFFFF">emails with
    554 a legal warning asking to not copy or redistribute freely the information
    555 they contain</span> are <strong>NOT</strong> acceptable for the mailing-list,
    556 such mail will as much as possible be discarded automatically, and are less
    557 likely to be answered if they made it to the list, <strong>DO NOT</strong>
    558 post to the list from an email address where such legal requirements are
    559 automatically added, get private paying support if you can't share
    560 information.</p>
    561 
    562 <p>Check the following <strong><span style="color: #FF0000">before
    563 posting</span></strong>:</p>
    564 <ul>
    565   <li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the
    566     search engine</a> to get information related to your problem.</li>
    567   <li>Make sure you are <a href="ftp://xmlsoft.org/libxml2/">using a recent
    568     version</a>, and that the problem still shows up in a recent version.</li>
    569   <li>Check the <a href="http://mail.gnome.org/archives/xml/">list
    570     archives</a> to see if the problem was reported already. In this case
    571     there is probably a fix available, similarly check the <a
    572     href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">registered
    573     open bugs</a>.</li>
    574   <li>Make sure you can reproduce the bug with xmllint or one of the test
    575     programs found in source in the distribution.</li>
    576   <li>Please send the command showing the error as well as the input (as an
    577     attachment)</li>
    578 </ul>
    579 
    580 <p>Then send the bug with associated information to reproduce it to the <a
    581 href="mailto:xml (a] gnome.org">xml (a] gnome.org</a> list; if it's really libxml
    582 related I will approve it. Please do not send mail to me directly, it makes
    583 things really hard to track and in some cases I am not the best person to
    584 answer a given question, ask on the list.</p>
    585 
    586 <p>To <span style="color: #E50000">be really clear about support</span>:</p>
    587 <ul>
    588   <li>Support or help <span style="color: #E50000">requests MUST be sent to
    589     the list or on bugzilla</span> in case of problems, so that the Question
    590     and Answers can be shared publicly. Failing to do so carries the implicit
    591     message "I want free support but I don't want to share the benefits with
    592     others" and is not welcome. I will automatically Carbon-Copy the
    593     xml (a] gnome.org mailing list for any technical reply made about libxml2 or
    594     libxslt.</li>
    595   <li>There is <span style="color: #E50000">no guarantee of support</span>. If
    596     your question remains unanswered after a week, repost it, making sure you
    597     gave all the detail needed and the information requested.</li>
    598   <li>Failing to provide information as requested or double checking first
    599     for prior feedback also carries the implicit message "the time of the
    600     library maintainers is less valuable than my time" and might not be
    601     welcome.</li>
    602 </ul>
    603 
    604 <p>Of course, bugs reported with a suggested patch for fixing them will
    605 probably be processed faster than those without.</p>
    606 
    607 <p>If you're looking for help, a quick look at <a
    608 href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually
    609 provide the answer. I usually send source samples when answering libxml2
    610 usage questions. The <a
    611 href="http://xmlsoft.org/html/book1.html">auto-generated documentation</a> is
    612 not as polished as I would like (i need to learn more about DocBook), but
    613 it's a good starting point.</p>
    614 
    615 <h2><a name="help">How to help</a></h2>
    616 
    617 <p>You can help the project in various ways, the best thing to do first is to
    618 subscribe to the mailing-list as explained before, check the <a
    619 href="http://mail.gnome.org/archives/xml/">archives </a>and the <a
    620 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Gnome bug
    621 database</a>:</p>
    622 <ol>
    623   <li>Provide patches when you find problems.</li>
    624   <li>Provide the diffs when you port libxml2 to a new platform. They may not
    625     be integrated in all cases but help pinpointing portability problems
    626   and</li>
    627   <li>Provide documentation fixes (either as patches to the code comments or
    628     as HTML diffs).</li>
    629   <li>Provide new documentations pieces (translations, examples, etc
    630   ...).</li>
    631   <li>Check the TODO file and try to close one of the items.</li>
    632   <li>Take one of the points raised in the archive or the bug database and
    633     provide a fix. <a href="mailto:daniel (a] veillard.com">Get in touch with me
    634     </a>before to avoid synchronization problems and check that the suggested
    635     fix will fit in nicely :-)</li>
    636 </ol>
    637 
    638 <h2><a name="Downloads">Downloads</a></h2>
    639 
    640 <p>The latest versions of libxml2 can be found on the <a
    641 href="ftp://xmlsoft.org/libxml2/">xmlsoft.org</a> server ( <a
    642 href="ftp://xmlsoft.org/libxml2/">FTP</a> and rsync are available), there are also
    643 mirrors (<a href="ftp://fr.rpmfind.net/pub/libxml/">France</a> and
    644 Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a
    645 mirror in Austria</a>). (NOTE that you need both the <a
    646 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a
    647 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a>
    648 packages installed to compile applications using libxml if using RPMs.)</p>
    649 
    650 <p>You can find all the history of libxml(2) and libxslt releases in the <a
    651 href="http://xmlsoft.org/sources/old/">old</a> directory. The precompiled
    652 Windows binaries made by Igor Zlatovic are available in the <a
    653 href="http://xmlsoft.org/sources/win32/">win32</a> directory.</p>
    654 
    655 <p>Binary ports:</p>
    656 <ul>
    657   <li>RPMs for x86_64 are available directly on <a
    658     href="ftp://xmlsoft.org/libxml2/">xmlsoft.org</a>, the source RPM will compile on
    659     any architecture supported.</li>
    660   <li><a href="mailto:igor (a] zlatkovic.com">Igor Zlatkovic</a> is now the
    661     maintainer of the Windows port, <a
    662     href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
    663     binaries</a>.</li>
    664   <li>OpenCSW provides <a
    665     href="http://opencsw.org/packages/libxml2">Solaris
    666   binaries</a>.</li>
    667   <li><a href="mailto:Steve.Ball (a] explain.com.au">Steve Ball</a> provides <a
    668     href="http://www.explain.com.au/oss/libxml2xslt.html">Mac Os X
    669     binaries</a>.</li>
    670   <li>The HP-UX porting center provides <a
    671     href="http://hpux.connect.org.uk/hppd/hpux/Gnome/">HP-UX binaries</a></li>
    672   <li>Bull provides precompiled <a
    673     href="http://gnome.bullfreeware.com/new_index.html">RPMs for AIX</a> as
    674     patr of their GNOME packages</li>
    675 </ul>
    676 
    677 <p>If you know other supported binary ports, please <a
    678 href="http://veillard.com/">contact me</a>.</p>
    679 
    680 <p><a name="Snapshot">Snapshot:</a></p>
    681 <ul>
    682   <li>Code from the GNOME GIT base libxml2 module, updated hourly <a
    683     href="ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gz">libxml2-git-snapshot.tar.gz</a>.</li>
    684   <li>Docs, content of the web site, the list archive included <a
    685     href="ftp://xmlsoft.org/libxml2/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li>
    686 </ul>
    687 
    688 <p><a name="Contribs">Contributions:</a></p>
    689 
    690 <p>I do accept external contributions, especially if compiling on another
    691 platform,  get in touch with the list to upload the package, wrappers for
    692 various languages have been provided, and can be found in the <a
    693 href="python.html">bindings section</a></p>
    694 
    695 <p>Libxml2 is also available from GIT:</p>
    696 <ul>
    697   <li><p>See <a href="http://git.gnome.org/browse/libxml2/">libxml2 Git web</a>.
    698          To checkout a local tree use:</p>
    699        <pre>git clone git://git.gnome.org/libxml2</pre>
    700   </li>
    701   <li>The <strong>libxslt</strong> module is also present 
    702       <a href="http://git.gnome.org/browse/libxslt/">there</a>.</li>
    703 </ul>
    704 
    705 <h2><a name="News">Releases</a></h2>
    706 
    707 <p>The <a href="ChangeLog.html">change log</a> describes the recents commits
    708 to the <a href="http://git.gnome.org/browse/libxml2/">GIT</a> code base.</p>
    709 
    710 <p>Here is the list of public releases:</p>
    711 
    712 <h3>2.9.2: Oct 16 2014</h3>
    713 <ul>
    714   <li>Security:<br/>
    715   Fix for CVE-2014-3660 billion laugh variant (Daniel Veillard),<br/>
    716   CVE-2014-0191 Do not fetch external parameter entities (Daniel Veillard)<br/>
    717   </li>
    718 
    719   <li>Bug Fixes:<br/>
    720   fix memory leak xml header encoding field with XML_PARSE_IGNORE_ENC (Bart De Schuymer),<br/>
    721   xmlmemory: handle realloc properly (Yegor Yefremov),<br/>
    722   Python generator bug raised by the const change (Daniel Veillard),<br/>
    723   Windows Critical sections not released correctly (Daniel Veillard),<br/>
    724   Parser error on repeated recursive entity expansion containing &amp;lt; (Daniel Veillard),<br/>
    725   xpointer : fixing Null Pointers (Gaurav Gupta),<br/>
    726   Remove Unnecessary Null check in xpointer.c (Gaurav Gupta),<br/>
    727   parser bug on misformed namespace attributes (Dennis Filder),<br/>
    728   Pointer dereferenced before null check (Daniel Veillard),<br/>
    729   Leak of struct addrinfo in xmlNanoFTPConnect() (Gaurav Gupta),<br/>
    730   Possible overflow in HTMLParser.c (Daniel Veillard),<br/>
    731   python/tests/sync.py assumes Python dictionaries are ordered (John Beck),<br/>
    732   Fix Enum check and missing break (Gaurav Gupta),<br/>
    733   xmlIO: Handle error returns from dup() (Philip Withnall),<br/>
    734   Fix a problem properly saving URIs (Daniel Veillard),<br/>
    735   wrong error column in structured error when parsing attribute values (Juergen Keil),<br/>
    736   wrong error column in structured error when skipping whitespace in xml decl (Juergen Keil),<br/>
    737   no error column in structured error handler for xml schema validation errors (Juergen Keil),<br/>
    738   Couple of Missing Null checks (Gaurav Gupta),<br/>
    739   Add couple of missing Null checks (Daniel Veillard),<br/>
    740   xmlschemastypes: Fix potential array overflow (Philip Withnall),<br/>
    741   runtest: Fix a memory leak on parse failure (Philip Withnall),<br/>
    742   xmlIO: Fix an FD leak on gzdopen() failure (Philip Withnall),<br/>
    743   xmlcatalog: Fix a memory leak on quit (Philip Withnall),<br/>
    744   HTMLparser: Correctly initialise a stack allocated structure (Philip Withnall),<br/>
    745   Check for tmon in _xmlSchemaDateAdd() is incorrect (David Kilzer),<br/>
    746   Avoid Possible Null Pointer in trio.c (Gaurav Gupta),<br/>
    747   Fix processing in SAX2 in case of an allocation failure (Daniel Veillard),<br/>
    748   XML Shell command "cd" does not handle "/" at end of path (Daniel Veillard),<br/>
    749   Fix various Missing Null checks (Gaurav Gupta),<br/>
    750   Fix a potential NULL dereference (Daniel Veillard),<br/>
    751   Add a couple of misisng check in xmlRelaxNGCleanupTree (Gaurav Gupta),<br/>
    752   Add a missing argument check (Gaurav Gupta),<br/>
    753   Adding a check in case of allocation error (Gaurav Gupta),<br/>
    754   xmlSaveUri() incorrectly recomposes URIs with rootless paths (Dennis Filder),<br/>
    755   Adding some missing NULL checks (Gaurav),<br/>
    756   Fixes for xmlInitParserCtxt (Daniel Veillard),<br/>
    757   Fix regressions introduced by CVE-2014-0191 patch (Daniel Veillard),<br/>
    758   erroneously ignores a validation error if no error callback set (Daniel Veillard),<br/>
    759   xmllint was not parsing the --c14n11 flag (Srgio Batista),<br/>
    760   Avoid Possible null pointer dereference in memory debug mode (Gaurav),<br/>
    761   Avoid Double Null Check (Gaurav),<br/>
    762   Restore context size and position after XPATH_OP_ARG (Nick Wellnhofer),<br/>
    763   Fix xmlParseInNodeContext() if node is not element (Daniel Veillard),<br/>
    764   Avoid a possible NULL pointer dereference (Gaurav),<br/>
    765   Fix xmlTextWriterWriteElement when a null content is given (Daniel Veillard),<br/>
    766   Fix an typo 'onrest' in htmlScriptAttributes (Daniel Veillard),<br/>
    767   fixing a ptotential uninitialized access (Daniel Veillard),<br/>
    768   Fix an fd leak in an error case (Daniel Veillard),<br/>
    769   Missing initialization for the catalog module (Daniel Veillard),<br/>
    770   Handling of XPath function arguments in error case (Nick Wellnhofer),<br/>
    771   Fix a couple of missing NULL checks (Gaurav),<br/>
    772   Avoid a possibility of dangling encoding handler (Gaurav),<br/>
    773   Fix HTML push parser to accept HTML_PARSE_NODEFDTD (Arnold Hendriks),<br/>
    774   Fix a bug loading some compressed files (Mike Alexander),<br/>
    775   Fix XPath node comparison bug (Gaurav),<br/>
    776   Type mismatch in xmlschemas.c (Gaurav),<br/>
    777   Type mismatch in xmlschemastypes.c (Gaurav),<br/>
    778   Avoid a deadcode in catalog.c (Daniel Veillard),<br/>
    779   run close socket on Solaris, same as we do on other platforms (Denis Pauk),<br/>
    780   Fix pointer dereferenced before null check (Gaurav),<br/>
    781   Fix a potential NULL dereference in tree code (Daniel Veillard),<br/>
    782   Fix potential NULL pointer dereferences in regexp code (Gaurav),<br/>
    783   xmllint --pretty crashed without following numeric argument (Tim Galeckas),<br/>
    784   Fix XPath expressions of the form '@ns:*' (Nick Wellnhofer),<br/>
    785   Fix XPath '//' optimization with predicates (Nick Wellnhofer),<br/>
    786   Clear up a potential NULL dereference (Daniel Veillard),<br/>
    787   Fix a possible NULL dereference (Gaurav),<br/>
    788   Avoid crash if allocation fails (Daniel Veillard),<br/>
    789   Remove occasional leading space in XPath number formatting (Daniel Veillard),<br/>
    790   Fix handling of mmap errors (Daniel Veillard),<br/>
    791   Catch malloc error and exit accordingly (Daniel Veillard),<br/>
    792   missing else in xlink.c (Ami Fischman),<br/>
    793   Fix a parsing bug on non-ascii element and CR/LF usage (Daniel Veillard),<br/>
    794   Fix a regression in xmlGetDocCompressMode() (Daniel Veillard),<br/>
    795   properly quote the namespace uris written out during c14n (Aleksey Sanin),<br/>
    796   Remove premature XInclude check on URI being relative (Alexey Neyman),<br/>
    797   Fix missing break on last() function for attributes (dcb),<br/>
    798   Do not URI escape in server side includes (Romain Bondue),<br/>
    799   Fix an error in xmlCleanupParser (Alexander Pastukhov)<br/>
    800   </li>
    801 
    802   <li>Documentation:<br/>
    803   typo in error messages "colon are forbidden from..." (Daniel Veillard),<br/>
    804   Fix a link to James SAX documentation old page (Daniel Veillard),<br/>
    805   Fix typos in relaxng.c (Jan Pokorn),<br/>
    806   Fix a doc typo (Daniel Veillard),<br/>
    807   Fix typos in {tree,xpath}.c (errror) (Jan Pokorn),<br/>
    808   Add limitations about encoding conversion (Daniel Veillard),<br/>
    809   Fix typos in xmlschemas{,types}.c (Jan Pokorn),<br/>
    810   Fix incorrect spelling entites-&gt;entities (Jan Pokorn),<br/>
    811   Forgot to document 2.9.1 release, regenerate docs (Daniel Veillard)<br/>
    812   </li>
    813 
    814   <li>Portability:<br/>
    815   AC_CONFIG_FILES and executable bit (Roumen Petrov),<br/>
    816   remove HAVE_CONFIG_H dependency in testlimits.c (Roumen Petrov),<br/>
    817   fix some tabs mixing incompatible with python3 (Roumen Petrov),<br/>
    818   Visual Studio 14 CTP defines snprintf() (Francis Dupont),<br/>
    819   OS400: do not try to copy unexisting doc files (Patrick Monnerat),<br/>
    820   OS400: use either configure.ac or configure.in. (Patrick Monnerat),<br/>
    821   os400: make-src.sh: create physical file with target CCSID (Patrick Monnerat),<br/>
    822   OS400: Add some more C macros equivalent procedures. (Patrick Monnerat),<br/>
    823   OS400: use C macros to implement equivalent RPG support procedures. (Patrick Monnerat),<br/>
    824   OS400: implement XPath macros as procedures for ILE/RPG support. (Patrick Monnerat),<br/>
    825   OS400: include in distribution tarball. (Patrick Monnerat),<br/>
    826   OS400: Add README: compilation directives and OS/400 specific stuff. (Patrick Monnerat),<br/>
    827   OS400: Add compilation scripts. (Patrick Monnerat),<br/>
    828   OS400: ILE RPG language header files. (Patrick Monnerat),<br/>
    829   OS400: implement some macros as functions for ILE/RPG language support (that as no macros). (Patrick Monnerat),<br/>
    830   OS400: UTF8&lt;--&gt;EBCDIC wrappers for system and external library calls (Patrick Monnerat),<br/>
    831   OS400: Easy character transcoding support (Patrick Monnerat),<br/>
    832   OS400: iconv functions compatibility wrappers and table builder. (Patrick Monnerat),<br/>
    833   OS400: create architecture directory. Implement dlfcn emulation. (Patrick Monnerat),<br/>
    834   Fix building when configuring without xpath and xptr (Daniel Veillard),<br/>
    835   configure: Add --with-python-install-dir (Jonas Eriksson),<br/>
    836   Fix compilation with minimum and xinclude. (Nicolas Le Cam),<br/>
    837   Compile out use of xmlValidateNCName() when not available. (Nicolas Le Cam),<br/>
    838   Fix compilation with minimum and schematron. (Nicolas Le Cam),<br/>
    839   Legacy needs xmlSAX2StartElement() and xmlSAX2EndElement(). (Nicolas Le Cam),<br/>
    840   Don't use xmlValidateName() when not available. (Nicolas Le Cam),<br/>
    841   Fix a portability issue on Windows (Longstreth Jon),<br/>
    842   Various portability patches for OpenVMS (Jacob (Jouk) Jansen),<br/>
    843   Use specific macros for portability to OS/400 (Patrick Monnerat),<br/>
    844   Add macros needed for OS/400 portability (Patrick Monnerat),<br/>
    845   Portability patch for fopen on OS/400 (Patrick Monnerat),<br/>
    846   Portability fixes for OS/400 (Patrick Monnerat),<br/>
    847   Improve va_list portability (Patrick Monnerat),<br/>
    848   Portability fix (Patrick Monnerat),<br/>
    849   Portability fix (Patrick Monnerat),<br/>
    850   Generic portability fix (Patrick Monnerat),<br/>
    851   Shortening lines in headers (Patrick Monnerat),<br/>
    852   build: Use pkg-config to find liblzma in preference to AC_CHECK_LIB (Philip Withnall),<br/>
    853   build: Add @LZMA_LIBS@ to libxmls pkg-config files (Philip Withnall),<br/>
    854   fix some tabs mixing incompatible with python3 (Daniel Veillard),<br/>
    855   add additional defines checks for support "./configure --with-minimum" (Denis Pauk),<br/>
    856   Another round of fixes for older versions of Python (Arfrever Frehtes Taifersar Arahesis),<br/>
    857   python: fix drv_libxml2.py for python3 compatibility (Alexandre Rostovtsev),<br/>
    858   python: Fix compiler warnings when building python3 bindings (Armin K),<br/>
    859   Fix for compilation with python 2.6.8 (Petr Sumbera)<br/>
    860   </li>
    861 
    862   <li>Improvements:<br/>
    863   win32/libxml2.def.src after rebuild in doc (Roumen Petrov),<br/>
    864   elfgcchack.h: more legacy needs xmlSAX2StartElement() and xmlSAX2EndElement() (Roumen Petrov),<br/>
    865   elfgcchack.h: add xmlXPathNodeEval and xmlXPathSetContextNode (Roumen Petrov),<br/>
    866   Provide cmake module (Samuel Martin),<br/>
    867   Fix a couple of issues raised by make dist (Daniel Veillard),<br/>
    868   Fix and add const qualifiers (Kurt Roeckx),<br/>
    869   Preparing for upcoming release of 2.9.2 (Daniel Veillard),<br/>
    870   Fix zlib and lzma libraries check via command line (Dmitriy),<br/>
    871   wrong error column in structured error when parsing end tag (Juergen Keil),<br/>
    872   doc/news.html: small update to avoid line join while generating NEWS. (Patrick Monnerat),<br/>
    873   Add methods for python3 iterator (Ron Angeles),<br/>
    874   Support element node traversal in document fragments. (Kyle VanderBeek),<br/>
    875   xmlNodeSetName: Allow setting the name to a substring of the currently set name (Tristan Van Berkom),<br/>
    876   Added macros for argument casts (Eric Zurcher),<br/>
    877   adding init calls to xml and html Read parsing entry points (Daniel Veillard),<br/>
    878   Get rid of 'REPLACEMENT CHARACTER' Unicode chars in xmlschemas.c (Jan Pokorn),<br/>
    879   Implement choice for name classes on attributes (Shaun McCance),<br/>
    880   Two small namespace tweaks (Daniel Veillard),<br/>
    881   xmllint --memory should fail on empty files (Daniel Veillard),<br/>
    882   Cast encoding name to char pointer to match arg type (Nikolay Sivov)<br/>
    883   </li>
    884 
    885   <li>Cleanups:<br/>
    886   Removal of old configure.in (Daniel Veillard),<br/>
    887   Unreachable code in tree.c (Gaurav Gupta),<br/>
    888   Remove a couple of dead conditions (Gaurav Gupta),<br/>
    889   Avoid some dead code and cleanup in relaxng.c (Gaurav),<br/>
    890   Drop not needed checks (Denis Pauk),<br/>
    891   Fix a wrong test (Daniel Veillard)<br/>
    892   </li>
    893 </ul>
    894 <h3>2.9.1: Apr 19 2013</h3>
    895 <ul>
    896   <li> Features:<br/>
    897     Support for Python3 (Daniel Veillard),<br/>
    898     Add xmlXPathSetContextNode and xmlXPathNodeEval (Alex Bligh)<br/>
    899   </li>
    900 
    901   <li> Documentation:<br/>
    902     Add documentation for xmllint --xpath (Daniel Veillard),<br/>
    903     Fix the URL of the SAX documentation from James (Daniel Veillard),<br/>
    904     Fix spelling of "length". (Michael Wood)<br/>
    905   </li>
    906 
    907   <li> Portability:<br/>
    908     Fix python bindings with versions older than 2.7 (Daniel Veillard),<br/>
    909     rebuild docs:Makefile.am (Roumen Petrov),<br/>
    910     elfgcchack.h after rebuild in doc (Roumen Petrov),<br/>
    911     elfgcchack for buf module (Roumen Petrov),<br/>
    912     Fix a uneeded and wrong extra link parameter (Daniel Veillard),<br/>
    913     Few cleanup patches for Windows (Denis Pauk),<br/>
    914     Fix rpmbuild --nocheck (Mark Salter),<br/>
    915     Fix for win32/configure.js and WITH_THREAD_ALLOC (Daniel Richard),<br/>
    916     Fix Broken multi-arch support in xml2-config (Daniel Veillard),<br/>
    917     Fix a portability issue for GCC &lt; 3.4.0 (Daniel Veillard),<br/>
    918     Windows build fixes (Daniel Richard),<br/>
    919     Fix a thread portability problem (Friedrich Haubensak),<br/>
    920     Downgrade autoconf requirement to 2.63 (Daniel Veillard)<br/>
    921   </li>
    922 
    923   <li> Bug Fixes:<br/>
    924     Fix a linking error for python bindings (Daniel Veillard),<br/>
    925     Fix a couple of return without value (Jri Aedla),<br/>
    926     Improve the hashing functions (Daniel Franke),<br/>
    927     Improve handling of xmlStopParser() (Daniel Veillard),<br/>
    928     Remove risk of lockup in dictionary initialization (Daniel Veillard),<br/>
    929     Activate detection of encoding in external subset (Daniel Veillard),<br/>
    930     Fix an output buffer flushing conversion bug (Mikhail Titov),<br/>
    931     Fix an old bug in xmlSchemaValidateOneElement (Csaba Lszl),<br/>
    932     Fix configure cannot remove messages (Gilles Espinasse),<br/>
    933     fix schema validation in combination with xsi:nil (Daniel Veillard),<br/>
    934     xmlCtxtReadFile doesn't work with literal IPv6 URLs (Steve Wolf),<br/>
    935     Fix a few problems with setEntityLoader (Alexey Neyman),<br/>
    936     Detect excessive entities expansion upon replacement (Daniel Veillard),<br/>
    937     Fix the flushing out of raw buffers on encoding conversions (Daniel,<br/>
    938 Veillard),<br/>
    939     Fix some buffer conversion issues (Daniel Veillard),<br/>
    940     When calling xmlNodeDump make sure we grow the buffer quickly (Daniel,<br/>
    941 Veillard),<br/>
    942     Fix an error in the progressive DTD parsing code (Dan Winship),<br/>
    943     xmllint should not load DTD by default when using the reader (Daniel,<br/>
    944 Veillard),<br/>
    945     Try IBM-037 when looking for EBCDIC handlers (Petr Sumbera),<br/>
    946     Fix potential out of bound access (Daniel Veillard),<br/>
    947     Fix large parse of file from memory (Daniel Veillard),<br/>
    948     Fix a bug in the nsclean option of the parser (Daniel Veillard),<br/>
    949     Fix a regression in 2.9.0 breaking validation while streaming (Daniel,<br/>
    950 Veillard),<br/>
    951     Remove potential calls to exit() (Daniel Veillard)<br/>
    952   </li>
    953 
    954   <li> Improvements:<br/>
    955     Regenerated API, and testapi, rebuild documentation (Daniel Veillard),<br/>
    956     Fix tree iterators broken by 2to3 script (Daniel Veillard),<br/>
    957     update all tests for Python3 and Python2 (Daniel Veillard),<br/>
    958     A few more fixes for python 3 affecting libxml2.py (Daniel Veillard),<br/>
    959     Fix compilation on Python3 (Daniel Veillard),<br/>
    960     Converting apibuild.py to python3 (Daniel Veillard),<br/>
    961     First pass at starting porting to python3 (Daniel Veillard),<br/>
    962     updated configure.in for python3 (Daniel Veillard),<br/>
    963     Add support for xpathRegisterVariable in Python (Shaun McCance),<br/>
    964     Added a regression tests from bug 694228 data (Daniel Veillard),<br/>
    965     Cache presence of '&lt;' in entities content (Daniel Veillard),<br/>
    966     Avoid extra processing on entities (Daniel Veillard),<br/>
    967     Python binding for xmlRegisterInputCallback (Alexey Neyman),<br/>
    968     Python bindings: DOM casts everything to xmlNode (Alexey Neyman),<br/>
    969     Define LIBXML_THREAD_ALLOC_ENABLED via xmlversion.h (Tim Starling),<br/>
    970     Adding streaming validation to runtest checks (Daniel Veillard),<br/>
    971     Add a --pushsmall option to xmllint (Daniel Veillard)<br/>
    972   </li>
    973 
    974   <li> Cleanups:<br/>
    975     Switched comment in file to UTF-8 encoding (Daniel Veillard),<br/>
    976     Extend gitignore (Daniel Veillard),<br/>
    977     Silent the new python test on input (Alexey Neyman),<br/>
    978     Cleanup of a duplicate test (Daniel Veillard),<br/>
    979     Cleanup on duplicate test expressions (Daniel Veillard),<br/>
    980     Fix compiler warning after 153cf15905cf4ec080612ada6703757d10caba1e (Patrick,<br/>
    981 Gansterer),<br/>
    982     Spec cleanups and a fix for multiarch support (Daniel Veillard),<br/>
    983     Silence a clang warning (Daniel Veillard),<br/>
    984     Cleanup the Copyright to be pure MIT Licence wording (Daniel Veillard),<br/>
    985     rand_seed should be static in dict.c (Wouter Van Rooy),<br/>
    986     Fix typos in parser comments (Jan Pokorn)<br/>
    987   </li>
    988 </ul>
    989 <h3>2.9.0: Sep 11 2012</h3>
    990 <ul>
    991   <li> Features:<br/>
    992     A few new API entry points,<br/>
    993     More resilient push parser mode,<br/>
    994     A lot of portability improvement,<br/>
    995     Faster XPath evaluation<br/>
    996   </li>
    997 
    998   <li> Documentation:<br/>
    999     xml2-config.1 markup error (Christian Weisgerber),<br/>
   1000     libxml(3) manpage typo fix (John Bradshaw),<br/>
   1001     More cleanups to the documentation part of libxml2 (Daniel Richard G)<br/>
   1002   </li>
   1003 
   1004   <li> Portability:<br/>
   1005     Bug 676544 - fails to build with --without-sax1 (Akira TAGOH),<br/>
   1006     fix builds not having stdint.h (Rob Richards),<br/>
   1007     GetProcAddressA is available only on WinCE (Daniel Veillard),<br/>
   1008     More updates and cleanups on autotools and Makefiles (Daniel Richard G),<br/>
   1009     More changes for Win32 compilation (Eric Zurcher),<br/>
   1010     Basic changes for Win32 builds of release 2.9.0: compile buf.c (Eric Zurcher),<br/>
   1011     Bundles all generated files for python into the distribution (Daniel Richard G),<br/>
   1012     Fix compiler warnings of wincecompat.c (Patrick Gansterer),<br/>
   1013     Fix non __GNUC__ build (Patrick Gansterer),<br/>
   1014     Fix windows unicode build (Patrick Gansterer),<br/>
   1015     clean redefinition of {v}snprintf in C-source (Roumen Petrov),<br/>
   1016     use xmlBuf... if DEBUG_INPUT is defined (Roumen Petrov),<br/>
   1017     fix runtests to use pthreads support for various Unix platforms (Daniel Richard G),<br/>
   1018     Various "make distcheck" and portability fixups 2nd part (Daniel Richard G),<br/>
   1019     Various "make distcheck" and portability fixups (Daniel Richard G),<br/>
   1020     Fix compilation on older Visual Studio (Daniel Veillard)<br/>
   1021   </li>
   1022 
   1023   <li> Bug Fixes:<br/>
   1024     Change the XPath code to percolate allocation errors (Daniel Veillard),<br/>
   1025     Fix reuse of xmlInitParser (Daniel Veillard),<br/>
   1026     Fix potential crash on entities errors (Daniel Veillard),<br/>
   1027     initialize var (Rob Richards),<br/>
   1028     Fix the XPath arity check to also check the XPath stack limits (Daniel Veillard),<br/>
   1029     Fix problem with specific and generic error handlers (Pietro Cerutti),<br/>
   1030     Avoid a potential infinite recursion (Daniel Veillard),<br/>
   1031     Fix an XSD error when generating internal automata (Daniel Veillard),<br/>
   1032     Patch for xinclude of text using multibyte characters (Vitaly Ostanin),<br/>
   1033     Fix a segfault on XSD validation on pattern error (Daniel Veillard),<br/>
   1034     Fix missing xmlsave.h module which was ignored in recent builds (Daniel Veillard),<br/>
   1035     Add a missing element check (Daniel Veillard),<br/>
   1036     Adding various checks on node type though the API (Daniel Veillard),<br/>
   1037     Namespace nodes can't be unlinked with xmlUnlinkNode (Daniel Veillard),<br/>
   1038     Fix make dist to include new private header files (Daniel Veillard),<br/>
   1039     More fixups on the push parser behaviour (Daniel Veillard),<br/>
   1040     Strengthen behaviour of the push parser in problematic situations (Daniel Veillard),<br/>
   1041     Enforce XML_PARSER_EOF state handling through the parser (Daniel Veillard),<br/>
   1042     Fixup limits parser (Daniel Veillard),<br/>
   1043     Do not fetch external parsed entities (Daniel Veillard),<br/>
   1044     Fix an error in previous commit (Aron Xu),<br/>
   1045     Fix entities local buffers size problems (Daniel Veillard),<br/>
   1046     Fix parser local buffers size problems (Daniel Veillard),<br/>
   1047     Fix a failure to report xmlreader parsing failures (Daniel Veillard)<br/>
   1048   </li>
   1049 
   1050   <li> Improvements:<br/>
   1051     Keep libxml2.syms when running "make distclean" (Daniel Veillard),<br/>
   1052     Allow to set the quoting character of an xmlWriter (Csaba Raduly),<br/>
   1053     Keep non-significant blanks node in HTML parser (Daniel Veillard),<br/>
   1054     Add a forbidden variable error number and message to XPath (Daniel Veillard),<br/>
   1055     Support long path names on WNT (Michael Stahl),<br/>
   1056     Improve HTML escaping of attribute on output (Daniel Veillard),<br/>
   1057     Handle ICU_LIBS as LIBADD, not LDFLAGS to prevent linking errors (Arfrever Frehtes Taifersar Arahesis),<br/>
   1058     Switching XPath node sorting to Timsort (Vojtech Fried),<br/>
   1059     Optimizing '//' in XPath expressions (Nick Wellnhofer),<br/>
   1060     Expose xmlBufShrink in the public tree API (Daniel Veillard),<br/>
   1061     Visible HTML elements close the head tag (Conrad Irwin),<br/>
   1062     Fix file and line report for XSD SAX and reader streaming validation (Daniel Veillard),<br/>
   1063     Fix const qualifyer to definition of xmlBufferDetach (Daniel Veillard),<br/>
   1064     minimize use of HAVE_CONFIG_H (Roumen Petrov),<br/>
   1065     fixup regression in Various "make distcheck" and portability fixups (Roumen Petrov),<br/>
   1066     Add support for big line numbers in error reporting (Daniel Veillard),<br/>
   1067     Avoid using xmlBuffer for serialization (Daniel Veillard),<br/>
   1068     Improve compatibility between xmlBuf and xmlBuffer (Daniel Veillard),<br/>
   1069     Provide new accessors for xmlOutputBuffer (Daniel Veillard),<br/>
   1070     Improvements for old buffer compatibility (Daniel Veillard),<br/>
   1071     Expand the limit test program (Daniel Veillard),<br/>
   1072     Improve error reporting on parser errors (Daniel Veillard),<br/>
   1073     Implement some default limits in the XPath module (Daniel Veillard),<br/>
   1074     Introduce some default parser limits (Daniel Veillard),<br/>
   1075     Cleanups and new limit APIs for dictionaries (Daniel Veillard),<br/>
   1076     Fixup for buf.c (Daniel Veillard),<br/>
   1077     Cleanup URI module memory allocation code (Daniel Veillard),<br/>
   1078     Extend testlimits (Daniel Veillard),<br/>
   1079     More avoid quadratic behaviour (Daniel Veillard),<br/>
   1080     Impose a reasonable limit on PI size (Daniel Veillard),<br/>
   1081     first version of testlimits new test (Daniel Veillard),<br/>
   1082     Avoid quadratic behaviour in some push parsing cases (Daniel Veillard),<br/>
   1083     Impose a reasonable limit on comment size (Daniel Veillard),<br/>
   1084     Impose a reasonable limit on attribute size (Daniel Veillard),<br/>
   1085     Harden the buffer code and make it more compatible (Daniel Veillard),<br/>
   1086     More cleanups for input/buffers code (Daniel Veillard),<br/>
   1087     Cleanup function xmlBufResetInput(),<br/> to set input from Buffer (Daniel Veillard)
   1088     Swicth the test program for characters to new input buffers (Daniel Veillard),<br/>
   1089     Convert the HTML tree module to the new buffers (Daniel Veillard),<br/>
   1090     Convert of the HTML parser to new input buffers (Daniel Veillard),<br/>
   1091     Convert the writer to new output buffer and save APIs (Daniel Veillard),<br/>
   1092     Convert XMLReader to the new input buffers (Daniel Veillard),<br/>
   1093     New saving functions using xmlBuf and conversion (Daniel Veillard),<br/>
   1094     Provide new xmlBuf based saving functions (Daniel Veillard),<br/>
   1095     Convert XInclude to the new input buffers (Daniel Veillard),<br/>
   1096     Convert catalog code to the new input buffers (Daniel Veillard),<br/>
   1097     Convert C14N to the new Input buffer (Daniel Veillard),<br/>
   1098     Convert xmlIO.c to the new input and output buffers (Daniel Veillard),<br/>
   1099     Convert XML parser to the new input buffers (Daniel Veillard),<br/>
   1100     Incompatible change to the Input and Output buffers (Daniel Veillard),<br/>
   1101     Adding new encoding function to deal with the new structures (Daniel Veillard),<br/>
   1102     Convert XPath to xmlBuf (Daniel Veillard),<br/>
   1103     Adding a new buf module for buffers (Daniel Veillard),<br/>
   1104     Memory error within SAX2 reuse common framework (Daniel Veillard),<br/>
   1105     Fix xmllint --xpath node initialization (Daniel Veillard)<br/>
   1106   </li>
   1107 
   1108   <li> Cleanups:<br/>
   1109     Various cleanups to avoid compiler warnings (Daniel Veillard),<br/>
   1110     Big space and tab cleanup (Daniel Veillard),<br/>
   1111     Followup to LibXML2 docs/examples cleanup patch (Daniel Veillard),<br/>
   1112     Second round of cleanups for LibXML2 docs/examples (Daniel Richard),<br/>
   1113     Remove all .cvsignore as they are not used anymore (Daniel Veillard),<br/>
   1114     Fix a Timsort function helper comment (Daniel Veillard),<br/>
   1115     Small cleanup for valgrind target (Daniel Veillard),<br/>
   1116     Patch for portability of latin characters in C files (Daniel Veillard),<br/>
   1117     Cleanup some of the parser code (Daniel Veillard),<br/>
   1118     Fix a variable name in comment (Daniel Veillard),<br/>
   1119     Regenerated testapi.c (Daniel Veillard),<br/>
   1120     Regenerating docs and API files (Daniel Veillard),<br/>
   1121     Small cleanup of unused variables in test (Daniel Veillard),<br/>
   1122     Expand .gitignore with more files (Daniel Veillard)<br/>
   1123   </li>
   1124 </ul>
   1125 <h3>2.8.0: May 23 2012</h3>
   1126 <ul>
   1127   <li>Features:
   1128   add lzma compression support (Anders F Bjorklund)
   1129   </li>
   1130 
   1131   <li>Documentation:
   1132     xmlcatalog: Add uri and delegateURI to possible add types in man page. (Ville Skytt),
   1133     Update README.tests (Daniel Veillard),
   1134     URI handling code is not OOM resilient (Daniel Veillard),
   1135     Fix an error in comment (Daniel Veillard),
   1136     Fixed bug #617016 (Daniel Mustieles),
   1137     Fixed two typos in the README document (Daniel Neel),
   1138     add generated html files (Anders F Bjorklund),
   1139     Clarify the need to use xmlFreeNode after xmlUnlinkNode (Daniel Veillard),
   1140     Improve documentation a bit (Daniel Veillard),
   1141     Updated URL for lxml python bindings (Daniel Veillard)
   1142   </li>
   1143 
   1144   <li>Portability:
   1145     Restore code for Windows compilation (Daniel Veillard),
   1146     Remove git error message during configure (Christian Dywan),
   1147     xmllint: Build fix for endTimer if !defined(HAVE_GETTIMEOFDAY) (Patrick R. Gansterer),
   1148     remove a bashism in confgure.in (John Hein),
   1149     undef ERROR if already defined (Patrick R. Gansterer),
   1150     Fix library problems with mingw-w64 (Michael Cronenworth),
   1151     fix windows build. ifdef addition from bug 666491 makes no sense (Rob Richards),
   1152     prefer native threads on win32 (Sam Thursfield),
   1153     Allow to compile with Visual Studio 2010 (Thomas Lemm),
   1154     Fix mingw's snprintf configure check (Andoni Morales),
   1155     fixed a 64bit big endian issue (Marcus Meissner),
   1156     Fix portability failure if netdb.h lacks NO_ADDRESS (Daniel Veillard),
   1157     Fix windows build from lzma addition (Rob Richards),
   1158     autogen: Only check for libtoolize (Colin Walters),
   1159     Fix the Windows build files (Patrick von Reth),
   1160     634846 Remove a linking option breaking Windows VC10 (Daniel Veillard),
   1161     599241 fix an initialization problem on Win64 (Andrew W. Nosenko),
   1162     fix win build (Rob Richards)
   1163   </li>
   1164 
   1165   <li>Bug fixes:
   1166     Part for rand_r checking missing (Daniel Veillard),
   1167     Cleanup on randomization (Daniel Veillard),
   1168     Fix undefined reference in python module (Pacho Ramos),
   1169     Fix a race in xmlNewInputStream (Daniel Veillard),
   1170     Fix weird streaming RelaxNG errors (Noam),
   1171     Fix various bugs in new code raised by the API checking (Daniel Veillard),
   1172     Fix various problems with "make dist" (Daniel Veillard),
   1173     Fix a memory leak in the xzlib code (Daniel Veillard),
   1174     HTML parser error with &lt;noscript&gt; in the &lt;head&gt; (Denis Pauk),
   1175     XSD: optional element in complex type extension (Remi Gacogne),
   1176     Fix html serialization error and htmlSetMetaEncoding() (Daniel Veillard),
   1177     Fix a wrong return value in previous patch (Daniel Veillard),
   1178     Fix an uninitialized variable use (Daniel Veillard),
   1179     Fix a compilation problem with --minimum (Brandon Slack),
   1180     Remove redundant and ungarded include of resolv.h (Daniel Veillard),
   1181     xinclude with parse="text" does not use the entity loader (Shaun McCance),
   1182     Allow to parse 1 byte HTML files (Denis Pauk),
   1183     Patch that fixes the skipping of the HTML_PARSE_NOIMPLIED flag (Martin Schrder),
   1184     Avoid memory leak if xmlParserInputBufferCreateIO fails (Lin Yi-Li),
   1185     Prevent an infinite loop when dumping a node with encoding problems (Timothy Elliott),
   1186     xmlParseNodeInContext problems with an empty document (Tim Elliott),
   1187     HTML element position is not detected propperly (Pavel Andrejs),
   1188     Fix an off by one pointer access (Jri Aedla),
   1189     Try to fix a problem with entities in SAX mode (Daniel Veillard),
   1190     Fix a crash with xmllint --path on empty results (Daniel Veillard),
   1191     Fixed bug #667946 (Daniel Mustieles),
   1192     Fix a logic error in Schemas Component Constraints (Ryan Sleevi),
   1193     Fix a wrong enum type use in Schemas Types (Nico Weber),
   1194     Fix SAX2 builder in case of undefined attributes namespace (Daniel Veillard),
   1195     Fix SAX2 builder in case of undefined element namespaces (Daniel Veillard),
   1196     fix reference to STDOUT_FILENO on MSVC (Tay Ray Chuan),
   1197     fix a pair of possible out of array char references (Daniel Veillard),
   1198     Fix an allocation error when copying entities (Daniel Veillard),
   1199     Make sure the parser returns when getting a Stop order (Chris Evans),
   1200     Fix some potential problems on reallocation failures(parser.c) (Xia Xinfeng),
   1201     Fix a schema type duration comparison overflow (Daniel Veillard),
   1202     Fix an unimplemented part in RNG value validation (Daniel Veillard),
   1203     Fix missing error status in XPath evaluation (Daniel Veillard),
   1204     Hardening of XPath evaluation (Daniel Veillard),
   1205     Fix an off by one error in encoding (Daniel Veillard),
   1206     Fix RELAX NG include bug #655288 (Shaun McCance),
   1207     Fix XSD validation bug #630130 (Toyoda Eizi),
   1208     Fix some potential problems on reallocation failures (Chris Evans),
   1209     __xmlRaiseError: fix use of the structured callback channel (Dmitry V. Levin),
   1210     __xmlRaiseError: fix the structured callback channel's data initialization (Dmitry V. Levin),
   1211     Fix memory corruption when xmlParseBalancedChunkMemoryInternal is called from xmlParseBalancedChunk (Rob Richards),
   1212     Small fix for previous commit (Daniel Veillard),
   1213     Fix a potential freeing error in XPath (Daniel Veillard),
   1214     Fix a potential memory access error (Daniel Veillard),
   1215     Reactivate the shared library versionning script (Daniel Veillard)
   1216   </li>
   1217 
   1218   <li>Improvements:
   1219     use mingw C99 compatible functions {v}snprintf instead those from MSVC runtime (Roumen Petrov),
   1220     New symbols added for the next release (Daniel Veillard),
   1221     xmlTextReader bails too quickly on error (Andy Lutomirski),
   1222     Use a hybrid allocation scheme in xmlNodeSetContent (Conrad Irwin),
   1223     Use buffers when constructing string node lists. (Conrad Irwin),
   1224     Add HTML parser support for HTML5 meta charset encoding declaration (Denis Pauk),
   1225     wrong message for double hyphen in comment XML error (Bryan Henderson),
   1226     Fix "make tst" to grab lzma lib too (Daniel Veillard),
   1227     Add "whereis" command to xmllint shell (Ryan),
   1228     Improve xmllint shell (Ryan),
   1229     add function xmlTextReaderRelaxNGValidateCtxt() (Noam Postavsky),
   1230     Add --system support to autogen.sh (Daniel Veillard),
   1231     Add hash randomization to hash and dict structures (Daniel Veillard),
   1232     included xzlib in dist (Anders F Bjorklund),
   1233     move xz/lzma helpers to separate included files (Anders F Bjorklund),
   1234     add generated devhelp files (Anders F Bjorklund),
   1235     add XML_WITH_LZMA to api (Anders F Bjorklund),
   1236     autogen.sh: Honor NOCONFIGURE environment variable (Colin Walters),
   1237     Improve the error report on undefined REFs (Daniel Veillard),
   1238     Add exception for new W3C PI xml-model (Daniel Veillard),
   1239     Add options to ignore the internal encoding (Daniel Veillard),
   1240     testapi: use the right type for the check (Stefan Kost),
   1241     various: handle return values of write calls (Stefan Kost),
   1242     testWriter: xmlTextWriterWriteFormatElement wants an int instead of a long int (Stefan Kost),
   1243     runxmlconf: update to latest testsuite version (Stefan Kost),
   1244     configure: add -Wno-long-long to CFLAGS (Stefan Kost),
   1245     configure: support silent automake rules if possible (Stefan Kost),
   1246     xmlmemory: add a cast as size_t has no portable printf modifier (Stefan Kost),
   1247     __xmlRaiseError: remove redundant schannel initialization (Dmitry V. Levin),
   1248     __xmlRaiseError: do cheap code check early (Dmitry V. Levin)
   1249   </li>
   1250 
   1251   <li>Cleanups:
   1252     Cleanups before 2.8.0-rc2 (Daniel Veillard),
   1253     Avoid an extra operation (Daniel Veillard),
   1254     Remove vestigial de-ANSI-fication support. (Javier Jardn),
   1255     autogen.sh: Fix typo (Javier Jardn),
   1256     Do not use unsigned but unsigned int (Daniel Veillard),
   1257     Remove two references to u_short (Daniel Veillard),
   1258     Fix -Wempty-body warning from clang (Nico Weber),
   1259     Cleanups of lzma support (Daniel Veillard),
   1260     Augment the list of ignored files (Daniel Veillard),
   1261     python: remove unused variable (Stefan Kost),
   1262     python: flag two unused args (Stefan Kost),
   1263     configure: acconfig.h is deprecated since autoconf-2.50 (Stefan Kost),
   1264     xpath: remove unused variable (Stefan Kost)
   1265   </li>
   1266 </ul>
   1267 <h3>2.7.8: Nov 4 2010</h3>
   1268 <ul>
   1269   <li> Features:
   1270     480323 add code to plug in ICU converters by default (Giuseppe Iuculano),
   1271     Add xmlSaveOption XML_SAVE_WSNONSIG (Adam Spragg)
   1272   </li>
   1273   <li> Documentation:
   1274     Fix devhelp documentation installation (Mike Hommey),
   1275     Fix web site encoding problems (Daniel Veillard),
   1276     Fix a couple of typo in HTML parser error messages (Michael Day),
   1277     Forgot to update the news page for 0.7.7 (Daniel Veillard)
   1278   </li>
   1279   <li> Portability:
   1280     607273 Fix python detection on MSys/Windows (LRN),
   1281     614087 Fix Socket API usage to allow Windows64 compilation (Ozkan Sezer),
   1282     Fix compilation with Clang (Koop Mast),
   1283     Fix Win32 build (Rob Richards)
   1284   </li>
   1285   <li> Bug Fixes:
   1286     595789 fix a remaining potential Solaris problem (Daniel Veillard),
   1287     617468 fix progressive HTML parsing with style using "'" (Denis Pauk),
   1288     616478 Fix xmllint shell write command (Gwenn Kahz),
   1289     614005 Possible erroneous HTML parsing on unterminated script (Pierre Belzile),
   1290     627987 Fix XSD IDC errors in imported schemas (Jim Panetta),
   1291     629325 XPath rounding errors first cleanup (Phil Shafer),
   1292     630140 fix iso995x encoding error (Daniel Veillard),
   1293     make sure htmlCtxtReset do reset the disableSAX field (Daniel Veillard),
   1294     Fix a change of semantic on XPath preceding and following axis (Daniel Veillard),
   1295     Fix a potential segfault due to weak symbols on pthreads (Mike Hommey),
   1296     Fix a leak in XPath compilation (Daniel Veillard),
   1297     Fix the semantic of XPath axis for namespace/attribute context nodes (Daniel Veillard),
   1298     Avoid a descriptor leak in catalog loading code (Carlo Bramini),
   1299     Fix a small bug in XPath evaluation code (Marius Wachtler),
   1300     Fix handling of XML-1.0 XML namespace declaration (Daniel Veillard),
   1301     Fix errors in XSD double validation check (Csaba Raduly),
   1302     Fix handling of apos in URIs (Daniel Veillard),
   1303     xmlTextReaderReadOuterXml should handle DTD (Rob Richards),
   1304     Autogen.sh needs to create m4 directory (Rob Richards)
   1305   </li>
   1306   <li> Improvements:
   1307     606592 update language ID parser to RFC 5646 (Daniel Veillard),
   1308     Sort python generated stubs (Mike Hommey),
   1309     Add an HTML parser option to avoid a default doctype (Daniel Veillard)
   1310   </li>
   1311   <li> Cleanups:
   1312     618831 don't ship generated files in git (Adrian Bunk),
   1313     Switch from the obsolete mkinstalldirs to AC_PROG_MKDIR_P (Adrian Bunk),
   1314     Various cleanups on encoding handling (Daniel Veillard),
   1315     Fix xmllint to use format=1 for default formatting (Adam Spragg),
   1316     Force _xmlSaveCtxt.format to be 0 or 1 (Adam Spragg),
   1317     Cleanup encoding pointer comparison (Nikolay Sivov),
   1318     Small code cleanup on previous patch (Daniel Veillard)
   1319   </li>
   1320 </ul>
   1321 <h3>2.7.7: Mar 15 2010</h3>
   1322 <ul>
   1323   <li> Improvements:
   1324     Adding a --xpath option to xmllint (Daniel Veillard),
   1325     Make HTML parser non-recursive (Eugene Pimenov)
   1326   </li>
   1327   <li> Portability:
   1328     relaxng.c: cast to allow compilation with sun studio 11 (Ben Walton),
   1329     Fix build failure on Sparc solaris (Roumen Petrov),
   1330     use autoreconf in autogen.sh (Daniel Veillard),
   1331     Fix build with mingw (Roumen Petrov),
   1332     Upgrade some of the configure and autogen (Daniel Veillard),
   1333     Fix relaxNG tests in runtest for Windows runtest.c: initialize ret (Rob Richards),
   1334     Fix a const warning in xmlNodeSetBase (Martin Trappel),
   1335     Fix python generator to not use deprecated xmllib (Daniel Veillard),
   1336     Update some automake files (Daniel Veillard),
   1337     598785 Fix nanohttp on Windows (spadix)
   1338   </li>
   1339   <li> Bug Fixes:
   1340     libxml violates the zlib interface and crashes (Mark Adler),
   1341     Fix broken escape behaviour in regexp ranges (Daniel Veillard),
   1342     Fix  missing win32 libraries in libxml-2.0.pc (Volker Grabsch),
   1343     Fix detection of python linker flags (Daniel Macks),
   1344     fix build error in libxml2/python (Paul Smith),
   1345     ChunkParser: Incorrect decoding of small xml files (Raul Hudea),
   1346     htmlCheckEncoding doesn't update input-end after shrink (Eugene Pimenov),
   1347     Fix a missing #ifdef (Daniel Veillard),
   1348     Fix encoding selection for xmlParseInNodeContext (Daniel Veillard),
   1349     xmlPreviousElementSibling mistake (Franois Delyon),
   1350     608773 add a missing check in xmlGROW (Daniel Veillard),
   1351     Fix xmlParseInNodeContext for HTML content (Daniel Veillard),
   1352     Fix lost namespace when copying node * tree.c: reconcile namespace if not found (Rob Richards),
   1353     Fix some missing commas in HTML element lists (Eugene Pimenov),
   1354     Correct variable type to unsigned (Nikolay Sivov),
   1355     Recognize ID attribute in HTML without DOCTYPE (Daniel Veillard),
   1356     Fix memory leak in xmlXPathEvalExpression() (Martin),
   1357     Fix an init bug in global.c (Kai Henning),
   1358     Fix xmlNodeSetBase() comment (Daniel Veillard),
   1359     Fix broken escape behaviour in regexp ranges (Daniel Veillard),
   1360     Don't give default HTML boolean attribute values in parser (Daniel Veillard),
   1361     xmlCtxtResetLastError should reset ctxt-errNo (Daniel Veillard)
   1362   </li>
   1363   <li> Cleanups:
   1364     Cleanup a couple of weirdness in HTML parser (Eugene Pimenov)
   1365   </li>
   1366 </ul>
   1367 <h3>2.7.6: Oct  6 2009</h3>
   1368 <ul>
   1369   <li> Bug Fixes:
   1370      Restore thread support in default configuration (Andrew W. Nosenko),
   1371      URI with no path parsing problem (Daniel Veillard),
   1372      Minor patch for conditional defines in threads.c (Eric Zurcher)
   1373   </li>
   1374 </ul>
   1375 <h3>2.7.5: Sep 24 2009</h3>
   1376 <ul>
   1377   <li> Bug Fixes:
   1378     Restore behavior of --with-threads without argument (Andrew W. Nosenko),
   1379     Fix memory leak when doc is NULL (Rob Richards),
   1380     595792 fixing a RelaxNG bug introduced in 2.7.4 (Daniel Veillard),
   1381     Fix a Relaxng bug raised by libvirt test suite (Daniel Veillard),
   1382     Fix a parsing problem with little data at startup (Daniel Veillard),
   1383     link python module with python library (Frederic Crozat),
   1384     594874 Forgot an fclose in xmllint (Daniel Veillard)
   1385   </li>
   1386   <li> Cleanup:
   1387     Adding symbols.xml to EXTRA_DIST (Daniel Veillard)
   1388   </li>
   1389 </ul>
   1390 <h3>2.7.4: Sep 10 2009</h3>
   1391 <ul>
   1392   <li>Improvements:
   1393     Switch to GIT (GNOME),
   1394     Add symbol versioning to libxml2 shared libs (Daniel Veillard)
   1395   </li>
   1396   <li>Portability:
   1397     593857 try to work around thread pbm MinGW 4.4 (Daniel Veillard),
   1398     594250 rename ATTRIBUTE_ALLOC_SIZE to avoid clashes (Daniel Veillard),
   1399     Fix Windows build * relaxng.c: fix windows build (Rob Richards),
   1400     Fix the globals.h to use XMLPUBFUN (Paul Smith),
   1401     Problem with extern extern in header (Daniel Veillard),
   1402     Add -lnetwork for compiling on Haiku (Scott McCreary),
   1403     Runtest portability patch for Solaris (Tim Rice),
   1404     Small patch to accomodate the Haiku OS (Scott McCreary),
   1405     584605 package VxWorks folder in the distribution (Daniel Veillard),
   1406     574017 Realloc too expensive on most platform (Daniel Veillard),
   1407     Fix windows build (Rob Richards),
   1408     545579 doesn't compile without schema support (Daniel Veillard),
   1409     xmllint use xmlGetNodePath when not compiled in (Daniel Veillard),
   1410     Try to avoid __imp__xmlFree link trouble on msys (Daniel Veillard),
   1411     Allow to select the threading system on Windows (LRN),
   1412     Fix Solaris binary links, cleanups (Daniel Veillard),
   1413     Bug 571059  MSVC doesn't work with the bakefile (Intron),
   1414     fix ATTRIBUTE_PRINTF header clash (Belgabor and Mike Hommey),
   1415     fixes for Borland/CodeGear/Embarcadero compilers (Eric Zurcher)
   1416   </li>
   1417   <li>Documentation:
   1418     544910 typo: "renciliateNs" (Leonid Evdokimov),
   1419     Add VxWorks to list of OSes (Daniel Veillard),
   1420     Regenerate the documentation and update for git (Daniel Veillard),
   1421     560524  xmlTextReaderLocalName description (Daniel Veillard),
   1422     Added sponsoring by AOE media for the server (Daniel Veillard),
   1423     updated URLs for GNOME (Vincent Lefevre),
   1424     more warnings about xmlCleanupThreads and xmlCleanupParser (Daniel Veillard)
   1425   </li>
   1426   <li>Bug fixes:
   1427     594514 memory leaks - duplicate initialization (MOD),
   1428     Wrong block opening in htmlNodeDumpOutputInternal (Daniel Veillard),
   1429     492317 Fix  Relax-NG validation problems (Daniel Veillard),
   1430     558452 fight with reg test and error report (Daniel Veillard),
   1431     558452 RNG compilation of optional multiple child (Daniel Veillard),
   1432     579746 XSD validation not correct / nilable groups (Daniel Veillard),
   1433     502960 provide namespace stack when parsing entity (Daniel Veillard),
   1434     566012 part 2 fix regresion tests and push mode (Daniel Veillard),
   1435     566012 autodetected encoding and encoding conflict (Daniel Veillard),
   1436     584220 xpointer(/) and xinclude problems (Daniel Veillard),
   1437     587663 Incorrect Attribute-Value Normalization (Daniel Veillard),
   1438     444994 HTML chunked failure for attribute with &lt;&gt; (Daniel Veillard),
   1439     Fix end of buffer char being split in XML parser (Daniel Veillard),
   1440     Non ASCII character may be split at buffer end (Adiel Mittmann),
   1441     440226 Add xmlXIncludeProcessTreeFlagsData API (Stefan Behnel),
   1442     572129 speed up parsing of large HTML text nodes (Markus Kull),
   1443     Fix HTML parsing with 0 character in CDATA (Daniel Veillard),
   1444     Fix SetGenericErrorFunc and SetStructured clash (Wang Lam),
   1445     566012  Incomplete EBCDIC parsing support (Martin Kogler),
   1446     541335 HTML avoid creating 2 head or 2 body element (Daniel Veillard),
   1447     541237 error correcting missing end tags in HTML (Daniel Veillard),
   1448     583439 missing line numbers in push mode (Daniel Veillard),
   1449     587867 xmllint --html --xmlout serializing as HTML (Daniel Veillard),
   1450     559501 avoid select and use poll for nanohttp (Raphael Prevost),
   1451     559410 -  Regexp bug on (...)? constructs (Daniel Veillard),
   1452     Fix a small problem on previous HTML parser patch (Daniel Veillard),
   1453     592430 -  HTML parser runs into endless loop (Daniel Veillard),
   1454     447899 potential double free in xmlFreeTextReader (Daniel Veillard),
   1455     446613 small validation bug mixed content with NS (Daniel Veillard),
   1456     Fix the problem of revalidating a doc with RNG (Daniel Veillard),
   1457     Fix xmlKeepBlanksDefault to not break indent (Nick Wellnhofer),
   1458     512131 refs from externalRef part need to be added (Daniel Veillard),
   1459     512131 crash in xmlRelaxNGValidateFullElement (Daniel Veillard),
   1460     588441 allow '.' in HTML Names even if invalid (Daniel Veillard),
   1461     582913 Fix htmlSetMetaEncoding() to be nicer (Daniel Veillard),
   1462     579317 Try to find the HTML encoding information (Daniel Veillard),
   1463     575875 don't output charset=html (Daniel Veillard),
   1464     571271 fix semantic of xsd:all with minOccurs=0 (Daniel Veillard),
   1465     570702 fix a bug in regexp determinism checking (Daniel Veillard),
   1466     567619 xmlValidateNotationUse missing param test (Daniel Veillard),
   1467     574393  utf-8 filename magic for compressed files (Hans Breuer),
   1468     Fix a couple of problems in the parser (Daniel Veillard),
   1469     585505  Document ids and refs populated by XSD (Wayne Jensen),
   1470     582906 XSD validating multiple imports of the same schema (Jason Childs),
   1471     Bug 582887  problems validating complex schemas (Jason Childs),
   1472     Bug 579729  fix XSD schemas parsing crash (Miroslav Bajtos),
   1473     576368  htmlChunkParser with special attributes (Jiri Netolicky),
   1474     Bug 565747  relax anyURI data character checking (Vincent Lefevre),
   1475     Preserve attributes of include start on tree copy (Petr Pajas),
   1476     Skip silently unrecognized XPointer schemes (Jakub Wilk),
   1477     Fix leak on SAX1, xmllint --sax1 option and debug (Daniel Veillard),
   1478     potential NULL dereference on non-glibc (Jim Meyering),
   1479     Fix an XSD validation crash (Daniel Veillard),
   1480     Fix a regression in streaming entities support (Daniel Veillard),
   1481     Fix a couple of ABI issues with C14N 1.1 (Aleksey Sanin),
   1482     Aleksey Sanin support for c14n 1.1 (Aleksey Sanin),
   1483     reader bug fix with entities (Daniel Veillard),
   1484     use options from current parser ctxt for external entities (Rob Richards),
   1485     581612 use %s to printf strings (Christian Persch),
   1486     584605 change the threading initialization sequence (Igor Novoseltsev),
   1487     580705 keep line numbers in HTML parser (Aaron Patterson),
   1488     581803 broken HTML table attributes init (Roland Steiner),
   1489     do not set error code in xmlNsWarn (Rob Richards),
   1490     564217 fix structured error handling problems,
   1491     reuse options from current parser for entities (Rob Richards),
   1492     xmlXPathRegisterNs should not allow enpty prefixes (Daniel Veillard),
   1493     add a missing check in xmlAddSibling (Kris Breuker),
   1494     avoid leaks on errors (Jinmei Tatuya)
   1495   </li>
   1496   <li>Cleanup:
   1497     Chasing dead assignments reported by clang-scan (Daniel Veillard),
   1498     A few more safety cleanup raised by scan (Daniel Veillard),
   1499     Fixing assorted potential problems raised by scan (Daniel Veillard),
   1500     Potential uninitialized arguments raised by scan (Daniel Veillard),
   1501     Fix a bunch of scan 'dead increments' and cleanup (Daniel Veillard),
   1502     Remove a pedantic warning (Daniel Veillard),
   1503     555833 always use rm -f in uninstall-local (Daniel Veillard),
   1504     542394 xmlRegisterOutputCallbacks MAX_INPUT_CALLBACK (Daniel Veillard),
   1505     Autoregenerate libxml2.syms automated checkings (Daniel Veillard),
   1506     Make xmlRecoverDoc const (Martin Trappel) (Daniel Veillard),
   1507     Both args of xmlStrcasestr are const (Daniel Veillard),
   1508     hide the nbParse* variables used for debugging (Mike Hommey),
   1509     570806 changed include of config.h (William M. Brack),
   1510     cleanups and error reports when xmlTextWriterVSprintf fails (Jinmei Tatuya)
   1511   </li>
   1512 </ul>
   1513 <h3>2.7.3: Jan 18 2009</h3>
   1514 <ul>
   1515   <li>Build fix: fix build when HTML support is not included.</li>
   1516   <li>Bug fixes: avoid memory overflow in gigantic text nodes,
   1517       indentation problem on the writed (Rob Richards),
   1518       xmlAddChildList pointer problem (Rob Richards and Kevin Milburn),
   1519       xmlAddChild problem with attribute (Rob Richards and Kris Breuker),
   1520       avoid a memory leak in an edge case (Daniel Zimmermann),
   1521       deallocate some pthread data (Alex Ott).</li>
   1522   <li>Improvements: configure option to avoid rebuilding docs (Adrian Bunk),
   1523       limit text nodes to 10MB max by default, add element traversal
   1524       APIs, add a parser option to enable pre 2.7 SAX behavior (Rob Richards),
   1525       add gcc malloc checking (Marcus Meissner), add gcc printf like functions
   1526       parameters checking (Marcus Meissner).</li>
   1527 </ul>
   1528 <h3>2.7.2: Oct 3 2008</h3>
   1529 <ul>
   1530     <li>Portability fix: fix solaris compilation problem, fix compilation
   1531         if XPath is not configured in</li>
   1532     <li>Bug fixes: nasty entity bug introduced in 2.7.0, restore old behaviour
   1533         when saving an HTML doc with an xml dump function, HTML UTF-8 parsing
   1534         bug, fix reader custom error handlers (Riccardo Scussat)
   1535     <li>Improvement: xmlSave options for more flexibility to save as
   1536         XML/HTML/XHTML, handle leading BOM in HTML documents</li>
   1537 </ul>
   1538 
   1539 <h3>2.7.1: Sep 1 2008</h3>
   1540 <ul>
   1541     <li>Portability fix: Borland C fix (Moritz Both)</li>
   1542     <li>Bug fixes: python serialization wrappers, XPath QName corner
   1543         case handking and leaks (Martin)</li>
   1544     <li>Improvement: extend the xmlSave to handle HTML documents and trees</li>
   1545     <li>Cleanup: python serialization wrappers</li>
   1546 </ul>
   1547 
   1548 <h3>2.7.0: Aug 30 2008</h3>
   1549 <ul>
   1550   <li>Documentation: switch ChangeLog to UTF-8, improve mutithreads and
   1551       xmlParserCleanup docs</li>
   1552   <li>Portability fixes: Older Win32 platforms (Rob Richards), MSVC
   1553       porting fix (Rob Richards), Mac OS X regression tests (Sven Herzberg),
   1554       non GNUCC builds (Rob Richards), compilation on Haiku (Andreas Frber)
   1555       </li>
   1556   <li>Bug fixes: various realloc problems (Ashwin), potential double-free
   1557       (Ashwin), regexp crash, icrash with invalid whitespace facets (Rob
   1558       Richards), pattern fix when streaming (William Brack), various XML
   1559       parsing and validation fixes based on the W3C regression tests, reader
   1560       tree skipping function fix (Ashwin), Schemas regexps escaping fix
   1561       (Volker Grabsch), handling of entity push errors (Ashwin), fix a slowdown
   1562       when encoder cant serialize characters on output</li>
   1563   <li>Code cleanup: compilation fix without the reader, without the output
   1564       (Robert Schwebel), python whitespace (Martin), many space/tabs cleanups,
   1565       serious cleanup of the entity handling code</li>
   1566   <li>Improvement: switch parser to XML-1.0 5th edition, add parsing flags
   1567       for old versions, switch URI parsing to RFC 3986,
   1568       add xmlSchemaValidCtxtGetParserCtxt (Holger Kaelberer),
   1569       new hashing functions for dictionnaries (based on Stefan Behnel work),
   1570       improve handling of misplaced html/head/body in HTML parser, better
   1571       regression test tools and code coverage display, better algorithms
   1572       to detect various versions of the billion laughts attacks, make
   1573       arbitrary parser limits avoidable as a parser option</li>
   1574 </ul>
   1575 <h3>2.6.32: Apr 8 2008</h3>
   1576 <ul>
   1577   <li>Documentation: returning heap memory to kernel (Wolfram Sang),
   1578       trying to clarify xmlCleanupParser() use, xmlXPathContext improvement
   1579       (Jack Jansen), improve the *Recover* functions documentation,
   1580       XmlNodeType doc link fix (Martijn Arts)</li>
   1581   <li>Bug fixes: internal subset memory leak (Ashwin), avoid problem with
   1582       paths starting with // (Petr Sumbera), streaming XSD validation callback
   1583       patches (Ashwin), fix redirection on port other than 80 (William Brack),
   1584       SAX2 leak (Ashwin), XInclude fragment of own document (Chris Ryan),
   1585       regexp bug with '.' (Andrew Tosh), flush the writer at the end of the
   1586       document (Alfred Mickautsch), output I/O bug fix (William Brack),
   1587       writer CDATA output after a text node (Alex Khesin), UTF-16 encoding
   1588       detection (William Brack), fix handling of empty CDATA nodes for Safari
   1589       team, python binding problem with namespace nodes, improve HTML parsing
   1590       (Arnold Hendriks), regexp automata build bug, memory leak fix (Vasily
   1591       Chekalkin), XSD test crash, weird system parameter entity parsing problem,
   1592       allow save to file:///X:/ windows paths, various attribute normalisation
   1593       problems, externalSubsetSplit fix (Ashwin), attribute redefinition in
   1594       the DTD (Ashwin), fix in char ref parsing check (Alex Khesin), many
   1595       out of memory handling fixes (Ashwin), XPath out of memory handling fixes
   1596       (Alvaro Herrera), various realloc problems (Ashwin), UCS4 encoding
   1597       conversion buffer size (Christian Fruth), problems with EatName
   1598       functions on memory errors, BOM handling in external parsed entities
   1599       (Mark Rowe)</li>
   1600   <li>Code cleanup: fix build under VS 2008 (David Wimsey), remove useless
   1601       mutex in xmlDict (Florent Guilian), Mingw32 compilation fix (Carlo
   1602       Bramini), Win and MacOS EOL cleanups (Florent Guiliani), iconv need
   1603       a const detection (Roumen Petrov), simplify xmlSetProp (Julien Charbon),
   1604       cross compilation fixes for Mingw (Roumen Petrov), SCO Openserver build
   1605       fix (Florent Guiliani), iconv uses const on Win32 (Rob Richards),
   1606       duplicate code removal (Ashwin), missing malloc test and error reports
   1607       (Ashwin), VMS makefile fix (Tycho Hilhorst)</li>
   1608   <li>improvements: better plug of schematron in the normal error handling
   1609       (Tobias Minich)</li>
   1610 </ul>
   1611 
   1612 <h3>2.6.31: Jan 11 2008</h3>
   1613 <ul>
   1614   <li>Security fix: missing of checks in UTF-8 parsing</li>
   1615   <li>Bug fixes: regexp bug, dump attribute from XHTML document, fix
   1616       xmlFree(NULL) to not crash in debug mode, Schematron parsing crash
   1617       (Rob Richards), global lock free on Windows (Marc-Antoine Ruel),
   1618       XSD crash due to double free (Rob Richards), indentation fix in
   1619       xmlTextWriterFullEndElement (Felipe Pena), error in attribute type
   1620       parsing if attribute redeclared, avoid crash in hash list scanner if
   1621       deleting elements, column counter bug fix (Christian Schmidt),
   1622       HTML embed element saving fix (Stefan Behnel), avoid -L/usr/lib
   1623       output from xml2-config (Fred Crozat), avoid an xmllint crash 
   1624       (Stefan Kost), don't stop HTML parsing on out of range chars.
   1625       </li>
   1626   <li>Code cleanup: fix open() call third argument, regexp cut'n paste
   1627       copy error, unused variable in __xmlGlobalInitMutexLock (Hannes Eder),
   1628       some make distcheck realted fixes (John Carr)</li>
   1629   <li>Improvements: HTTP Header: includes port number (William Brack),
   1630       testURI --debug option, </li>
   1631 </ul>
   1632 <h3>2.6.30: Aug 23 2007</h3>
   1633 <ul>
   1634   <li>Portability: Solaris crash on error handling, windows path fixes
   1635       (Roland Schwarz and Rob Richards), mingw build (Roland Schwarz)</li>
   1636   <li>Bugfixes: xmlXPathNodeSetSort problem (William Brack), leak when
   1637       reusing a writer for a new document (Dodji Seketeli), Schemas
   1638       xsi:nil handling patch (Frank Gross), relative URI build problem
   1639       (Patrik Fimml), crash in xmlDocFormatDump, invalid char in comment
   1640       detection bug, fix disparity with xmlSAXUserParseMemory, automata
   1641       generation for complex regexp counts problems, Schemas IDC import
   1642       problems (Frank Gross), xpath predicate evailation error handling
   1643       (William Brack)</li>
   1644 </ul>
   1645 <h3>2.6.29: Jun 12 2007</h3>
   1646 <ul>
   1647   <li>Portability: patches from Andreas Stricke for WinCEi,
   1648       fix compilation warnings (William Brack), avoid warnings on Apple OS/X
   1649       (Wendy Doyle and Mark Rowe), Windows compilation and threading
   1650       improvements (Rob Richards), compilation against old Python versions,
   1651       new GNU tar changes (Ryan Hill)</li>
   1652   <li>Documentation: xmlURIUnescapeString comment, </li>
   1653   <li>Bugfixes: xmlBufferAdd problem (Richard Jones), 'make valgrind'
   1654       flag fix (Richard Jones), regexp interpretation of \,
   1655       htmlCreateDocParserCtxt (Jean-Daniel Dupas), configure.in
   1656       typo (Bjorn Reese), entity content failure, xmlListAppend() fix
   1657       (Georges-Andr Silber), XPath number serialization (William Brack),
   1658       nanohttp gzipped stream fix (William Brack and Alex Cornejo),
   1659       xmlCharEncFirstLine typo (Mark Rowe), uri bug (Franois Delyon),
   1660       XPath string value of PI nodes (William Brack), XPath node set
   1661       sorting bugs (William Brack), avoid outputting namespace decl
   1662       dups in the writer (Rob Richards), xmlCtxtReset bug, UTF-8 encoding
   1663       error handling, recustion on next in catalogs, fix a Relax-NG crash,
   1664       workaround wrong file: URIs, htmlNodeDumpFormatOutput on attributes,
   1665       invalid character in attribute detection bug, big comments before 
   1666       internal subset streaming bug, HTML parsing of attributes with : in
   1667       the name, IDness of name in HTML (Dagfinn I. Mannsker) </li>
   1668   <li>Improvement: keep URI query parts in raw form (Richard Jones),
   1669       embed tag support in HTML (Michael Day) </li>
   1670 </ul>
   1671 
   1672 <h3>2.6.28: Apr 17 2007</h3>
   1673 <ul>
   1674   <li>Documentation: comment fixes (Markus Keim), xpath comments fixes too
   1675       (James Dennett)</li>
   1676   <li>Bug fixes: XPath bug (William Brack), HTML parser autoclose stack usage
   1677       (Usamah Malik), various regexp bug fixes (DV and William), path conversion
   1678       on Windows (Igor Zlatkovic), htmlCtxtReset fix (Michael Day), XPath
   1679       principal node of axis bug, HTML serialization of some codepoint
   1680       (Steven Rainwater), user data propagation in XInclude (Michael Day),
   1681       standalone and XML decl detection (Michael Day), Python id ouptut
   1682       for some id, fix the big python string memory leak, URI parsing fixes
   1683       (Stphane Bidoul and William), long comments parsing bug (William),
   1684       concurrent threads initialization (Ted Phelps), invalid char
   1685       in text XInclude (William), XPath memory leak (William), tab in
   1686       python problems (Andreas Hanke), XPath node comparison error
   1687       (Oleg Paraschenko), cleanup patch for reader (Julien Reichel),
   1688       XML Schemas attribute group (William), HTML parsing problem (William),
   1689       fix char 0x2d in regexps (William), regexp quantifier range with
   1690       min occurs of 0 (William), HTML script/style parsing (Mike Day)</li>
   1691   <li>Improvement: make xmlTextReaderSetup() public</li>
   1692   <li>Compilation and postability: fix a missing include problem (William),
   1693       __ss_familly on AIX again (Bjrn Wiberg), compilation without zlib
   1694       (Michael Day), catalog patch for Win32 (Christian Ehrlicher),
   1695       Windows CE fixes (Andreas Stricke)</li>
   1696   <li>Various CVS to SVN infrastructure changes</li>
   1697 </ul>
   1698 <h3>2.6.27: Oct 25 2006</h3>
   1699 <ul>
   1700   <li>Portability fixes: file names on windows (Roland Schwingel, 
   1701       Emelyanov Alexey), windows compile fixup (Rob Richards), 
   1702       AIX iconv() is apparently case sensitive</li>
   1703   <li>improvements: Python XPath types mapping (Nic Ferrier), XPath optimization
   1704       (Kasimier), add xmlXPathCompiledEvalToBoolean (Kasimier), Python node
   1705       equality and comparison (Andreas Pakulat), xmlXPathCollectAndTest
   1706       improvememt (Kasimier), expose if library was compiled with zlib 
   1707       support (Andrew Nosenko), cache for xmlSchemaIDCMatcher structs
   1708       (Kasimier), xmlTextConcat should work with comments and PIs (Rob
   1709       Richards), export htmlNewParserCtxt needed by Michael Day, refactoring
   1710       of catalog entity loaders (Michael Day), add XPointer support to 
   1711       python bindings (Ross Reedstrom, Brian West and Stefan Anca), 
   1712       try to sort out most file path to URI conversions and xmlPathToUri,
   1713       add --html --memory case to xmllint</li>
   1714   <li>building fix: fix --with-minimum (Felipe Contreras), VMS fix, 
   1715       const'ification of HTML parser structures (Matthias Clasen),
   1716       portability fix (Emelyanov Alexey), wget autodetection (Peter
   1717       Breitenlohner),  remove the build path recorded in the python
   1718       shared module, separate library flags for shared and static builds
   1719       (Mikhail Zabaluev), fix --with-minimum --with-sax1 builds, fix
   1720       --with-minimum --with-schemas builds</li>
   1721   <li>bug fix: xmlGetNodePath fix (Kasimier), xmlDOMWrapAdoptNode and
   1722       attribute (Kasimier), crash when using the recover mode, 
   1723       xmlXPathEvalExpr problem (Kasimier), xmlXPathCompExprAdd bug (Kasimier),
   1724       missing destry in xmlFreeRMutex (Andrew Nosenko), XML Schemas fixes
   1725       (Kasimier), warning on entities processing, XHTML script and style
   1726       serialization (Kasimier), python generator for long types, bug in
   1727       xmlSchemaClearValidCtxt (Bertrand Fritsch), xmlSchemaXPathEvaluate
   1728       allocation bug (Marton Illes), error message end of line (Rob Richards),
   1729       fix attribute serialization in writer (Rob Richards), PHP4 DTD validation
   1730       crasher, parser safety patch (Ben Darnell), _private context propagation
   1731       when parsing entities (with Michael Day), fix entities behaviour when 
   1732       using SAX, URI to file path fix (Mikhail Zabaluev), disapearing validity
   1733       context, arg error in SAX callback (Mike Hommey), fix mixed-content
   1734       autodetect when using --noblanks, fix xmlIOParseDTD error handling,
   1735       fix bug in xmlSplitQName on special Names, fix Relax-NG element content
   1736       validation bug, fix xmlReconciliateNs bug, fix potential attribute 
   1737       XML parsing bug, fix line/column accounting in XML parser, chunking bug
   1738       in the HTML parser on script, try to detect obviously buggy HTML
   1739       meta encoding indications, bugs with encoding BOM and xmlSaveDoc, 
   1740       HTML entities in attributes parsing, HTML minimized attribute values,
   1741       htmlReadDoc and htmlReadIO were broken, error handling bug in
   1742       xmlXPathEvalExpression (Olaf Walkowiak), fix a problem in
   1743       htmlCtxtUseOptions, xmlNewInputFromFile could leak (Marius Konitzer),
   1744       bug on misformed SSD regexps (Christopher Boumenot)
   1745       </li>
   1746   <li>documentation: warning about XML_PARSE_COMPACT (Kasimier Buchcik),
   1747       fix xmlXPathCastToString documentation, improve man pages for
   1748       xmllitn and xmlcatalog (Daniel Leidert), fixed comments of a few
   1749       functions</li>
   1750 </ul>
   1751 <h3>2.6.26: Jun 6 2006</h3>
   1752 <ul>
   1753   <li>portability fixes: Python detection (Joseph Sacco), compilation
   1754     error(William Brack and Graham Bennett), LynxOS patch (Olli Savia)</li>
   1755   <li>bug fixes: encoding buffer problem, mix of code and data in
   1756     xmlIO.c(Kjartan Maraas), entities in XSD validation (Kasimier Buchcik),
   1757     variousXSD validation fixes (Kasimier), memory leak in pattern (Rob
   1758     Richards andKasimier), attribute with colon in name (Rob Richards), XPath
   1759     leak inerror reporting (Aleksey Sanin), XInclude text include of
   1760     selfdocument.</li>
   1761   <li>improvements: Xpath optimizations (Kasimier), XPath object
   1762     cache(Kasimier)</li>
   1763 </ul>
   1764 
   1765 <h3>2.6.25: Jun 6 2006:</h3>
   1766 
   1767 <p>Do not use or package 2.6.25</p>
   1768 
   1769 <h3>2.6.24: Apr 28 2006</h3>
   1770 <ul>
   1771   <li>Portability fixes: configure on Windows, testapi compile on windows
   1772       (Kasimier Buchcik, venkat naidu), Borland C++ 6 compile (Eric Zurcher),
   1773       HP-UX compiler workaround (Rick Jones), xml2-config bugfix, gcc-4.1
   1774       cleanups, Python detection scheme (Joseph Sacco), UTF-8 file paths on
   1775       Windows (Roland Schwingel).
   1776       </li>
   1777   <li>Improvements: xmlDOMWrapReconcileNamespaces xmlDOMWrapCloneNode (Kasimier
   1778       Buchcik), XML catalog debugging (Rick Jones), update to Unicode 4.01.</li>
   1779   <li>Bug fixes: xmlParseChunk() problem in 2.6.23, xmlParseInNodeContext()
   1780       on HTML docs, URI behaviour on Windows (Rob Richards), comment streaming
   1781       bug, xmlParseComment (with William Brack), regexp bug fixes (DV &amp;
   1782       Youri Golovanov), xmlGetNodePath on text/CDATA (Kasimier),
   1783       one Relax-NG interleave bug, xmllint --path and --valid,
   1784       XSD bugfixes (Kasimier), remove debug
   1785       left in Python bindings (Nic Ferrier), xmlCatalogAdd bug (Martin Cole),
   1786       xmlSetProp fixes (Rob Richards), HTML IDness (Rob Richards), a large
   1787       number of cleanups and small fixes based on Coverity reports, bug
   1788       in character ranges, Unicode tables const (Aivars Kalvans), schemas
   1789       fix (Stefan Kost), xmlRelaxNGParse error deallocation, 
   1790       xmlSchemaAddSchemaDoc error deallocation, error handling on unallowed
   1791       code point, ixmllint --nonet to never reach the net (Gary Coady),
   1792       line break in writer after end PI (Jason Viers). </li>
   1793   <li>Documentation: man pages updates and cleanups (Daniel Leidert).</li>
   1794   <li>New features: Relax NG structure error handlers.</li>
   1795 </ul>
   1796 
   1797 <h3>2.6.23: Jan 5 2006</h3>
   1798 <ul>
   1799   <li>portability fixes: Windows (Rob Richards), getaddrinfo on Windows
   1800     (Kolja Nowak, Rob Richards), icc warnings (Kjartan Maraas),
   1801     --with-minimum compilation fixes (William Brack), error case handling fix
   1802     on Solaris (Albert Chin), don't use 'list' as parameter name reported by
   1803     Samuel Diaz Garcia, more old Unices portability fixes (Albert Chin),
   1804     MinGW compilation (Mark Junker), HP-UX compiler warnings (Rick
   1805   Jones),</li>
   1806   <li>code cleanup: xmlReportError (Adrian Mouat), remove xmlBufferClose
   1807     (Geert Jansen), unreachable code (Oleksandr Kononenko), refactoring
   1808     parsing code (Bjorn Reese)</li>
   1809   <li>bug fixes: xmlBuildRelativeURI and empty path (William Brack),
   1810     combinatory explosion and performances in regexp code, leak in
   1811     xmlTextReaderReadString(), xmlStringLenDecodeEntities problem (Massimo
   1812     Morara), Identity Constraints bugs and a segfault (Kasimier Buchcik),
   1813     XPath pattern based evaluation bugs (DV &amp; Kasimier),
   1814     xmlSchemaContentModelDump() memory leak (Kasimier), potential leak in
   1815     xmlSchemaCheckCSelectorXPath(), xmlTextWriterVSprintf() misuse of
   1816     vsnprintf (William Brack), XHTML serialization fix (Rob Richards), CRLF
   1817     split problem (William), issues with non-namespaced attributes in
   1818     xmlAddChild() xmlAddNextSibling() and xmlAddPrevSibling() (Rob Richards),
   1819     HTML parsing of script, Python must not output to stdout (Nic Ferrier),
   1820     exclusive C14N namespace visibility (Aleksey Sanin), XSD dataype
   1821     totalDigits bug (Kasimier Buchcik), error handling when writing to an
   1822     xmlBuffer (Rob Richards), runtest schemas error not reported (Hisashi
   1823     Fujinaka), signed/unsigned problem in date/time code (Albert Chin), fix
   1824     XSI driven XSD validation (Kasimier), parsing of xs:decimal (Kasimier),
   1825     fix DTD writer output (Rob Richards), leak in xmlTextReaderReadInnerXml
   1826     (Gary Coady), regexp bug affecting schemas (Kasimier), configuration of
   1827     runtime debugging (Kasimier), xmlNodeBufGetContent bug on entity refs
   1828     (Oleksandr Kononenko), xmlRegExecPushString2 bug (Sreeni Nair),
   1829     compilation and build fixes (Michael Day), removed dependancies on
   1830     xmlSchemaValidError (Kasimier), bug with &lt;xml:foo/&gt;, more XPath
   1831     pattern based evaluation fixes (Kasimier)</li>
   1832   <li>improvements: XSD Schemas redefinitions/restrictions (Kasimier
   1833     Buchcik), node copy checks and fix for attribute (Rob Richards), counted
   1834     transition bug in regexps, ctxt-&gt;standalone = -2 to indicate no
   1835     standalone attribute was found, add xmlSchemaSetParserStructuredErrors()
   1836     (Kasimier Buchcik), add xmlTextReaderSchemaValidateCtxt() to API
   1837     (Kasimier), handle gzipped HTTP resources (Gary Coady), add
   1838     htmlDocDumpMemoryFormat. (Rob Richards),</li>
   1839   <li>documentation: typo (Michael Day), libxml man page (Albert Chin), save
   1840     function to XML buffer (Geert Jansen), small doc fix (Aron Stansvik),</li>
   1841 </ul>
   1842 
   1843 <h3>2.6.22: Sep 12 2005</h3>
   1844 <ul>
   1845   <li>build fixes: compile without schematron (Stphane Bidoul)</li>
   1846   <li>bug fixes: xmlDebugDumpNode on namespace node (Oleg Paraschenko)i,
   1847     CDATA push parser bug, xmlElemDump problem with XHTML1 doc,
   1848     XML_FEATURE_xxx clash with expat headers renamed XML_WITH_xxx, fix some
   1849     output formatting for meta element (Rob Richards), script and style
   1850     XHTML1 serialization (David Madore), Attribute derivation fixups in XSD
   1851     (Kasimier Buchcik), better IDC error reports (Kasimier Buchcik)</li>
   1852   <li>improvements: add XML_SAVE_NO_EMPTY xmlSaveOption (Rob Richards), add
   1853     XML_SAVE_NO_XHTML xmlSaveOption, XML Schemas improvements preparing for
   1854     derive (Kasimier Buchcik).</li>
   1855   <li>documentation: generation of gtk-doc like docs, integration with
   1856     devhelp.</li>
   1857 </ul>
   1858 
   1859 <h3>2.6.21: Sep 4 2005</h3>
   1860 <ul>
   1861   <li>build fixes: Cygwin portability fixes (Gerrit P. Haase), calling
   1862     convention problems on Windows (Marcus Boerger), cleanups based on Linus'
   1863     sparse tool, update of win32/configure.js (Rob Richards), remove warnings
   1864     on Windows(Marcus Boerger), compilation without SAX1, detection of the
   1865     Python binary, use $GCC inestad of $CC = 'gcc' (Andrew W. Nosenko),
   1866     compilation/link with threads and old gcc, compile problem by C370 on
   1867     Z/OS,</li>
   1868   <li>bug fixes: http_proxy environments (Peter Breitenlohner), HTML UTF-8
   1869     bug (Jiri Netolicky), XPath NaN compare bug (William Brack),
   1870     htmlParseScript potential bug, Schemas regexp handling of spaces, Base64
   1871     Schemas comparisons NIST passes, automata build error xsd:all,
   1872     xmlGetNodePath for namespaced attributes (Alexander Pohoyda), xmlSchemas
   1873     foreign namespaces handling, XML Schemas facet comparison (Kupriyanov
   1874     Anatolij), xmlSchemaPSimpleTypeErr error report (Kasimier Buchcik), xml:
   1875     namespace ahndling in Schemas (Kasimier), empty model group in Schemas
   1876     (Kasimier), wilcard in Schemas (Kasimier), URI composition (William),
   1877     xs:anyType in Schemas (Kasimier), Python resolver emmitting error
   1878     messages directly, Python xmlAttr.parent (Jakub Piotr Clapa), trying to
   1879     fix the file path/URI conversion, xmlTextReaderGetAttribute fix (Rob
   1880     Richards), xmlSchemaFreeAnnot memleak (Kasimier), HTML UTF-8
   1881     serialization, streaming XPath, Schemas determinism detection problem,
   1882     XInclude bug, Schemas context type (Dean Hill), validation fix (Derek
   1883     Poon), xmlTextReaderGetAttribute[Ns] namespaces (Rob Richards), Schemas
   1884     type fix (Kuba Nowakowski), UTF-8 parser bug, error in encoding handling,
   1885     xmlGetLineNo fixes, bug on entities handling, entity name extraction in
   1886     error handling with XInclude, text nodes in HTML body tags (Gary Coady),
   1887     xml:id and IDness at the treee level fixes, XPath streaming patterns
   1888   bugs.</li>
   1889   <li>improvements: structured interfaces for schemas and RNG error reports
   1890     (Marcus Boerger), optimization of the char data inner loop parsing
   1891     (thanks to Behdad Esfahbod for the idea), schematron validation though
   1892     not finished yet, xmlSaveOption to omit XML declaration, keyref match
   1893     error reports (Kasimier), formal expression handling code not plugged
   1894     yet, more lax mode for the HTML parser, parser XML_PARSE_COMPACT option
   1895     for text nodes allocation.</li>
   1896   <li>documentation: xmllint man page had --nonet duplicated</li>
   1897 </ul>
   1898 
   1899 <h3>2.6.20: Jul 10 2005</h3>
   1900 <ul>
   1901   <li>build fixes: Windows build (Rob Richards), Mingw compilation (Igor
   1902     Zlatkovic), Windows Makefile (Igor), gcc warnings (Kasimier and
   1903     andriy (a] google.com), use gcc weak references to pthread to avoid the
   1904     pthread dependancy on Linux, compilation problem (Steve Nairn), compiling
   1905     of subset (Morten Welinder), IPv6/ss_family compilation (William Brack),
   1906     compilation when disabling parts of the library, standalone test
   1907     distribution.</li>
   1908   <li>bug fixes: bug in lang(), memory cleanup on errors (William Brack),
   1909     HTTP query strings (Aron Stansvik), memory leak in DTD (William), integer
   1910     overflow in XPath (William), nanoftp buffer size, pattern "." apth fixup
   1911     (Kasimier), leak in tree reported by Malcolm Rowe, replaceNode patch
   1912     (Brent Hendricks), CDATA with NULL content (Mark Vakoc), xml:base fixup
   1913     on XInclude (William), pattern fixes (William), attribute bug in
   1914     exclusive c14n (Aleksey Sanin), xml:space and xml:lang with SAX2 (Rob
   1915     Richards), namespace trouble in complex parsing (Malcolm Rowe), XSD type
   1916     QNames fixes (Kasimier), XPath streaming fixups (William), RelaxNG bug
   1917     (Rob Richards), Schemas for Schemas fixes (Kasimier), removal of ID (Rob
   1918     Richards), a small RelaxNG leak, HTML parsing in push mode bug (James
   1919     Bursa), failure to detect UTF-8 parsing bugs in CDATA sections,
   1920     areBlanks() heuristic failure, duplicate attributes in DTD bug
   1921   (William).</li>
   1922   <li>improvements: lot of work on Schemas by Kasimier Buchcik both on
   1923     conformance and streaming, Schemas validation messages (Kasimier Buchcik,
   1924     Matthew Burgess), namespace removal at the python level (Brent
   1925     Hendricks), Update to new Schemas regression tests from W3C/Nist
   1926     (Kasimier), xmlSchemaValidateFile() (Kasimier), implementation of
   1927     xmlTextReaderReadInnerXml and xmlTextReaderReadOuterXml (James Wert),
   1928     standalone test framework and programs, new DOM import APIs
   1929     xmlDOMWrapReconcileNamespaces() xmlDOMWrapAdoptNode() and
   1930     xmlDOMWrapRemoveNode(), extension of xmllint capabilities for SAX and
   1931     Schemas regression tests, xmlStopParser() available in pull mode too,
   1932     ienhancement to xmllint --shell namespaces support, Windows port of the
   1933     standalone testing tools (Kasimier and William),
   1934     xmlSchemaValidateStream() xmlSchemaSAXPlug() and xmlSchemaSAXUnplug() SAX
   1935     Schemas APIs, Schemas xmlReader support.</li>
   1936 </ul>
   1937 
   1938 <h3>2.6.19: Apr 02 2005</h3>
   1939 <ul>
   1940   <li>build fixes: drop .la from RPMs, --with-minimum build fix (William
   1941     Brack), use XML_SOCKLEN_T instead of SOCKLEN_T because it breaks with AIX
   1942     5.3 compiler, fixed elfgcchack.h generation and PLT reduction code on
   1943     Linux/ELF/gcc4</li>
   1944   <li>bug fixes: schemas type decimal fixups (William Brack), xmmlint return
   1945     code (Gerry Murphy), small schemas fixes (Matthew Burgess and GUY
   1946     Fabrice), workaround "DAV:" namespace brokeness in c14n (Aleksey Sanin),
   1947     segfault in Schemas (Kasimier Buchcik), Schemas attribute validation
   1948     (Kasimier), Prop related functions and xmlNewNodeEatName (Rob Richards),
   1949     HTML serialization of name attribute on a elements, Python error handlers
   1950     leaks and improvement (Brent Hendricks), uninitialized variable in
   1951     encoding code, Relax-NG validation bug, potential crash if
   1952     gnorableWhitespace is NULL, xmlSAXParseDoc and xmlParseDoc signatures,
   1953     switched back to assuming UTF-8 in case no encoding is given at
   1954     serialization time</li>
   1955   <li>improvements: lot of work on Schemas by Kasimier Buchcik on facets
   1956     checking and also mixed handling.</li>
   1957   <li></li>
   1958 </ul>
   1959 
   1960 <h3>2.6.18: Mar 13 2005</h3>
   1961 <ul>
   1962   <li>build fixes: warnings (Peter Breitenlohner), testapi.c generation,
   1963     Bakefile support (Francesco Montorsi), Windows compilation (Joel Reed),
   1964     some gcc4 fixes, HP-UX portability fixes (Rick Jones).</li>
   1965   <li>bug fixes: xmlSchemaElementDump namespace (Kasimier Buchcik), push and
   1966     xmlreader stopping on non-fatal errors, thread support for dictionnaries
   1967     reference counting (Gary Coady), internal subset and push problem, URL
   1968     saved in xmlCopyDoc, various schemas bug fixes (Kasimier), Python paths
   1969     fixup (Stephane Bidoul), xmlGetNodePath and namespaces, xmlSetNsProp fix
   1970     (Mike Hommey), warning should not count as error (William Brack),
   1971     xmlCreatePushParser empty chunk, XInclude parser flags (William), cleanup
   1972     FTP and HTTP code to reuse the uri parsing and IPv6 (William),
   1973     xmlTextWriterStartAttributeNS fix (Rob Richards), XMLLINT_INDENT being
   1974     empty (William), xmlWriter bugs (Rob Richards), multithreading on Windows
   1975     (Rich Salz), xmlSearchNsByHref fix (Kasimier), Python binding leak (Brent
   1976     Hendricks), aliasing bug exposed by gcc4 on s390, xmlTextReaderNext bug
   1977     (Rob Richards), Schemas decimal type fixes (William Brack),
   1978     xmlByteConsumed static buffer (Ben Maurer).</li>
   1979   <li>improvement: speedup parsing comments and DTDs, dictionnary support for
   1980     hash tables, Schemas Identity constraints (Kasimier), streaming XPath
   1981     subset, xmlTextReaderReadString added (Bjorn Reese), Schemas canonical
   1982     values handling (Kasimier), add xmlTextReaderByteConsumed (Aron
   1983   Stansvik),</li>
   1984   <li>Documentation: Wiki support (Joel Reed)</li>
   1985 </ul>
   1986 
   1987 <h3>2.6.17: Jan 16 2005</h3>
   1988 <ul>
   1989   <li>build fixes: Windows, warnings removal (William Brack),
   1990     maintainer-clean dependency(William), build in a different directory
   1991     (William), fixing --with-minimum configure build (William), BeOS build
   1992     (Marcin Konicki), Python-2.4 detection (William), compilation on AIX (Dan
   1993     McNichol)</li>
   1994   <li>bug fixes: xmlTextReaderHasAttributes (Rob Richards), xmlCtxtReadFile()
   1995     to use the catalog(s), loop on output (William Brack), XPath memory leak,
   1996     ID deallocation problem (Steve Shepard), debugDumpNode crash (William),
   1997     warning not using error callback (William), xmlStopParser bug (William),
   1998     UTF-16 with BOM on DTDs (William), namespace bug on empty elements in
   1999     push mode (Rob Richards), line and col computations fixups (Aleksey
   2000     Sanin), xmlURIEscape fix (William), xmlXPathErr on bad range (William),
   2001     patterns with too many steps, bug in RNG choice optimization, line number
   2002     sometimes missing.</li>
   2003   <li>improvements: XSD Schemas (Kasimier Buchcik), python generator
   2004     (William), xmlUTF8Strpos speedup (William), unicode Python strings
   2005     (William), XSD error reports (Kasimier Buchcik), Python __str__ call
   2006     serialize().</li>
   2007   <li>new APIs: added xmlDictExists(), GetLineNumber and GetColumnNumber for
   2008     the xmlReader (Aleksey Sanin), Dynamic Shared Libraries APIs (mostly Joel
   2009     Reed), error extraction API from regexps, new XMLSave option for format
   2010     (Phil Shafer)</li>
   2011   <li>documentation: site improvement (John Fleck), FAQ entries
   2012   (William).</li>
   2013 </ul>
   2014 
   2015 <h3>2.6.16: Nov 10 2004</h3>
   2016 <ul>
   2017   <li>general hardening and bug fixing crossing all the API based on new
   2018     automated regression testing</li>
   2019   <li>build fix: IPv6 build and test on AIX (Dodji Seketeli)</li>
   2020   <li>bug fixes: problem with XML::Libxml reported by Petr Pajas,  encoding
   2021     conversion functions return values, UTF-8 bug affecting XPath reported by
   2022     Markus Bertheau, catalog problem with NULL entries (William Brack)</li>
   2023   <li>documentation: fix to xmllint man page, some API function descritpion
   2024     were updated.</li>
   2025   <li>improvements: DTD validation APIs provided at the Python level (Brent
   2026     Hendricks)</li>
   2027 </ul>
   2028 
   2029 <h3>2.6.15: Oct 27 2004</h3>
   2030 <ul>
   2031   <li>security fixes on the nanoftp and nanohttp modules</li>
   2032   <li>build fixes: xmllint detection bug in configure, building outside the
   2033     source tree (Thomas Fitzsimmons)</li>
   2034   <li>bug fixes: HTML parser on broken ASCII chars in names (William), Python
   2035     paths (Malcolm Tredinnick), xmlHasNsProp and default namespace (William),
   2036     saving to python file objects (Malcolm Tredinnick), DTD lookup fix
   2037     (Malcolm), save back &lt;group&gt; in catalogs (William), tree build
   2038     fixes (DV and Rob Richards), Schemas memory bug, structured error handler
   2039     on Python 64bits, thread local memory deallocation, memory leak reported
   2040     by Volker Roth, xmlValidateDtd in the presence of an internal subset,
   2041     entities and _private problem (William), xmlBuildRelativeURI error
   2042     (William).</li>
   2043   <li>improvements: better XInclude error reports (William), tree debugging
   2044     module and tests, convenience functions at the Reader API (Graham
   2045     Bennett), add support for PI in the HTML parser.</li>
   2046 </ul>
   2047 
   2048 <h3>2.6.14: Sep 29 2004</h3>
   2049 <ul>
   2050   <li>build fixes: configure paths for xmllint and xsltproc, compilation
   2051     without HTML parser, compilation warning cleanups (William Brack &amp;
   2052     Malcolm Tredinnick), VMS makefile update (Craig Berry),</li>
   2053   <li>bug fixes: xmlGetUTF8Char (William Brack), QName properties (Kasimier
   2054     Buchcik), XInclude testing, Notation serialization, UTF8ToISO8859x
   2055     transcoding (Mark Itzcovitz), lots of XML Schemas cleanup and fixes
   2056     (Kasimier), ChangeLog cleanup (Stepan Kasal), memory fixes (Mark Vakoc),
   2057     handling of failed realloc(), out of bound array adressing in Schemas
   2058     date handling, Python space/tabs cleanups (Malcolm Tredinnick), NMTOKENS
   2059     E20 validation fix (Malcolm),</li>
   2060   <li>improvements: added W3C XML Schemas testsuite (Kasimier Buchcik), add
   2061     xmlSchemaValidateOneElement (Kasimier), Python exception hierearchy
   2062     (Malcolm Tredinnick), Python libxml2 driver improvement (Malcolm
   2063     Tredinnick), Schemas support for xsi:schemaLocation,
   2064     xsi:noNamespaceSchemaLocation, xsi:type (Kasimier Buchcik)</li>
   2065 </ul>
   2066 
   2067 <h3>2.6.13: Aug 31 2004</h3>
   2068 <ul>
   2069   <li>build fixes: Windows and zlib (Igor Zlatkovic), -O flag with gcc,
   2070     Solaris compiler warning, fixing RPM BuildRequires,</li>
   2071   <li>fixes: DTD loading on Windows (Igor), Schemas error reports APIs
   2072     (Kasimier Buchcik), Schemas validation crash, xmlCheckUTF8 (William Brack
   2073     and Julius Mittenzwei), Schemas facet check (Kasimier), default namespace
   2074     problem (William), Schemas hexbinary empty values, encoding error could
   2075     genrate a serialization loop.</li>
   2076   <li>Improvements: Schemas validity improvements (Kasimier), added --path
   2077     and --load-trace options to xmllint</li>
   2078   <li>documentation: tutorial update (John Fleck)</li>
   2079 </ul>
   2080 
   2081 <h3>2.6.12: Aug 22 2004</h3>
   2082 <ul>
   2083   <li>build fixes: fix --with-minimum, elfgcchack.h fixes (Peter
   2084     Breitenlohner), perl path lookup (William), diff on Solaris (Albert
   2085     Chin), some 64bits cleanups.</li>
   2086   <li>Python: avoid a warning with 2.3 (William Brack), tab and space mixes
   2087     (William), wrapper generator fixes (William), Cygwin support (Gerrit P.
   2088     Haase), node wrapper fix (Marc-Antoine Parent), XML Schemas support
   2089     (Torkel Lyng)</li>
   2090   <li>Schemas: a lot of bug fixes and improvements from Kasimier Buchcik</li>
   2091   <li>fixes: RVT fixes (William), XPath context resets bug (William), memory
   2092     debug (Steve Hay), catalog white space handling (Peter Breitenlohner),
   2093     xmlReader state after attribute reading (William), structured error
   2094     handler (William), XInclude generated xml:base fixup (William), Windows
   2095     memory reallocation problem (Steve Hay), Out of Memory conditions
   2096     handling (William and Olivier Andrieu), htmlNewDoc() charset bug,
   2097     htmlReadMemory init (William), a posteriori validation DTD base
   2098     (William), notations serialization missing, xmlGetNodePath (Dodji),
   2099     xmlCheckUTF8 (Diego Tartara), missing line numbers on entity
   2100   (William)</li>
   2101   <li>improvements: DocBook catalog build scrip (William), xmlcatalog tool
   2102     (Albert Chin), xmllint --c14n option, no_proxy environment (Mike Hommey),
   2103     xmlParseInNodeContext() addition, extend xmllint --shell, allow XInclude
   2104     to not generate start/end nodes, extend xmllint --version to include CVS
   2105     tag (William)</li>
   2106   <li>documentation: web pages fixes, validity API docs fixes (William)
   2107     schemas API fix (Eric Haszlakiewicz), xmllint man page (John Fleck)</li>
   2108 </ul>
   2109 
   2110 <h3>2.6.11: July 5 2004</h3>
   2111 <ul>
   2112   <li>Schemas: a lot of changes and improvements by Kasimier Buchcik for
   2113     attributes, namespaces and simple types.</li>
   2114   <li>build fixes: --with-minimum (William Brack),  some gcc cleanup
   2115     (William), --with-thread-alloc (William)</li>
   2116   <li>portability: Windows binary package change (Igor Zlatkovic), Catalog
   2117     path on Windows</li>
   2118   <li>documentation: update to the tutorial (John Fleck), xmllint return code
   2119     (John Fleck), man pages (Ville Skytta),</li>
   2120   <li>bug fixes: C14N bug serializing namespaces (Aleksey Sanin), testSAX
   2121     properly initialize the library (William), empty node set in XPath
   2122     (William), xmlSchemas errors (William), invalid charref problem pointed
   2123     by Morus Walter, XInclude xml:base generation (William), Relax-NG bug
   2124     with div processing (William), XPointer and xml:base problem(William),
   2125     Reader and entities, xmllint return code for schemas (William), reader
   2126     streaming problem (Steve Ball), DTD serialization problem (William),
   2127     libxml.m4 fixes (Mike Hommey), do not provide destructors as methods on
   2128     Python classes, xmlReader buffer bug, Python bindings memory interfaces
   2129     improvement (with Stphane Bidoul), Fixed the push parser to be back to
   2130     synchronous behaviour.</li>
   2131   <li>improvement: custom per-thread I/O enhancement (Rob Richards), register
   2132     namespace in debug shell (Stefano Debenedetti), Python based regression
   2133     test for non-Unix users (William), dynamically increase the number of
   2134     XPath extension functions in Python and fix a memory leak (Marc-Antoine
   2135     Parent and William)</li>
   2136   <li>performance: hack done with Arjan van de Ven to reduce ELF footprint
   2137     and generated code on Linux, plus use gcc runtime profiling to optimize
   2138     the code generated in the RPM packages.</li>
   2139 </ul>
   2140 
   2141 <h3>2.6.10: May 17 2004</h3>
   2142 <ul>
   2143   <li>Web page generated for ChangeLog</li>
   2144   <li>build fixes: --without-html problems, make check without make all</li>
   2145   <li>portability: problem with xpath.c on Windows (MSC and Borland), memcmp
   2146     vs. strncmp on Solaris, XPath tests on Windows (Mark Vakoc), C++ do not
   2147     use "list" as parameter name, make tests work with Python 1.5 (Ed
   2148   Davis),</li>
   2149   <li>improvements: made xmlTextReaderMode public, small buffers resizing
   2150     (Morten Welinder), add --maxmem option to xmllint, add
   2151     xmlPopInputCallback() for Matt Sergeant, refactoring of serialization
   2152     escaping, added escaping customization</li>
   2153   <li>bugfixes: xsd:extension (Taihei Goi), assorted regexp bugs (William
   2154     Brack), xmlReader end of stream problem, node deregistration with reader,
   2155     URI escaping and filemanes,  XHTML1 formatting (Nick Wellnhofer), regexp
   2156     transition reduction (William), various XSD Schemas fixes (Kasimier
   2157     Buchcik), XInclude fallback problem (William), weird problems with DTD
   2158     (William), structured error handler callback context (William), reverse
   2159     xmlEncodeSpecialChars() behaviour back to escaping '"'</li>
   2160 </ul>
   2161 
   2162 <h3>2.6.9: Apr 18 2004</h3>
   2163 <ul>
   2164   <li>implement xml:id Working Draft, relaxed XPath id() checking</li>
   2165   <li>bugfixes: xmlCtxtReset (Brent Hendricks), line number and CDATA (Dave
   2166     Beckett), Relax-NG compilation (William Brack), Regexp patches (with
   2167     William), xmlUriEscape (Mark Vakoc), a Relax-NG notAllowed problem (with
   2168     William), Relax-NG name classes compares (William), XInclude duplicate
   2169     fallback (William), external DTD encoding detection (William), a DTD
   2170     validation bug (William), xmlReader Close() fix, recusive extention
   2171     schemas</li>
   2172   <li>improvements: use xmlRead* APIs in test tools (Mark Vakoc), indenting
   2173     save optimization, better handle IIS broken HTTP redirect  behaviour (Ian
   2174     Hummel), HTML parser frameset (James Bursa), libxml2-python RPM
   2175     dependancy, XML Schemas union support (Kasimier Buchcik), warning removal
   2176     clanup (William), keep ChangeLog compressed when installing from RPMs</li>
   2177   <li>documentation: examples and xmlDocDumpMemory docs (John Fleck), new
   2178     example (load, xpath, modify, save), xmlCatalogDump() comments,</li>
   2179   <li>Windows: Borland C++ builder (Eric Zurcher), work around Microsoft
   2180     compiler NaN handling bug (Mark Vakoc)</li>
   2181 </ul>
   2182 
   2183 <h3>2.6.8: Mar 23 2004</h3>
   2184 <ul>
   2185   <li>First step of the cleanup of the serialization code and APIs</li>
   2186   <li>XML Schemas: mixed content (Adam Dickmeiss), QName handling fixes (Adam
   2187     Dickmeiss), anyURI for "" (John Belmonte)</li>
   2188   <li>Python: Canonicalization C14N support added (Anthony Carrico)</li>
   2189   <li>xmlDocCopyNode() extension (William)</li>
   2190   <li>Relax-NG: fix when processing XInclude results (William), external
   2191     reference in interleave (William), missing error on &lt;choice&gt;
   2192     failure (William), memory leak in schemas datatype facets.</li>
   2193   <li>xmlWriter: patch for better DTD support (Alfred Mickautsch)</li>
   2194   <li>bug fixes: xmlXPathLangFunction memory leak (Mike Hommey and William
   2195     Brack), no ID errors if using HTML_PARSE_NOERROR, xmlcatalog fallbacks to
   2196     URI on SYSTEM lookup failure, XInclude parse flags inheritance (William),
   2197     XInclude and XPointer fixes for entities (William), XML parser bug
   2198     reported by Holger Rauch, nanohttp fd leak (William),  regexps char
   2199     groups '-' handling (William), dictionnary reference counting problems,
   2200     do not close stderr.</li>
   2201   <li>performance patches from Petr Pajas</li>
   2202   <li>Documentation fixes: XML_CATALOG_FILES in man pages (Mike Hommey)</li>
   2203   <li>compilation and portability fixes: --without-valid, catalog cleanups
   2204     (Peter Breitenlohner), MingW patch (Roland Schwingel), cross-compilation
   2205     to Windows (Christophe de Vienne),  --with-html-dir fixup (Julio Merino
   2206     Vidal), Windows build (Eric Zurcher)</li>
   2207 </ul>
   2208 
   2209 <h3>2.6.7: Feb 23 2004</h3>
   2210 <ul>
   2211   <li>documentation: tutorial updates (John Fleck), benchmark results</li>
   2212   <li>xmlWriter: updates and fixes (Alfred Mickautsch, Lucas Brasilino)</li>
   2213   <li>XPath optimization (Petr Pajas)</li>
   2214   <li>DTD ID handling optimization</li>
   2215   <li>bugfixes: xpath number with  &gt; 19 fractional (William Brack), push
   2216     mode with unescaped '&gt;' characters, fix xmllint --stream --timing, fix
   2217     xmllint --memory --stream memory usage, xmlAttrSerializeTxtContent
   2218     handling NULL, trying to fix Relax-NG/Perl interface.</li>
   2219   <li>python: 2.3 compatibility, whitespace fixes (Malcolm Tredinnick)</li>
   2220   <li>Added relaxng option to xmllint --shell</li>
   2221 </ul>
   2222 
   2223 <h3>2.6.6: Feb 12 2004</h3>
   2224 <ul>
   2225   <li>nanohttp and nanoftp: buffer overflow error on URI parsing (Igor and
   2226     William) reported by Yuuichi Teranishi</li>
   2227   <li>bugfixes: make test and path issues, xmlWriter attribute serialization
   2228     (William Brack), xmlWriter indentation (William), schemas validation
   2229     (Eric Haszlakiewicz), XInclude dictionnaries issues (William and Oleg
   2230     Paraschenko), XInclude empty fallback (William), HTML warnings (William),
   2231     XPointer in XInclude (William), Python namespace serialization,
   2232     isolat1ToUTF8 bound error (Alfred Mickautsch), output of parameter
   2233     entities in internal subset (William), internal subset bug in push mode,
   2234     &lt;xs:all&gt; fix (Alexey Sarytchev)</li>
   2235   <li>Build: fix for automake-1.8 (Alexander Winston), warnings removal
   2236     (Philip Ludlam), SOCKLEN_T detection fixes (Daniel Richard), fix
   2237     --with-minimum configuration.</li>
   2238   <li>XInclude: allow the 2001 namespace without warning.</li>
   2239   <li>Documentation: missing example/index.html (John Fleck), version
   2240     dependancies (John Fleck)</li>
   2241   <li>reader API: structured error reporting (Steve Ball)</li>
   2242   <li>Windows compilation: mingw, msys (Mikhail Grushinskiy), function
   2243     prototype (Cameron Johnson), MSVC6 compiler warnings, _WINSOCKAPI_
   2244   patch</li>
   2245   <li>Parsers: added xmlByteConsumed(ctxt) API to get the byte offest in
   2246     input.</li>
   2247 </ul>
   2248 
   2249 <h3>2.6.5: Jan 25 2004</h3>
   2250 <ul>
   2251   <li>Bugfixes: dictionnaries for schemas (William Brack), regexp segfault
   2252     (William), xs:all problem (William), a number of XPointer bugfixes
   2253     (William), xmllint error go to stderr, DTD validation problem with
   2254     namespace, memory leak (William), SAX1 cleanup and minimal options fixes
   2255     (Mark Vadoc), parser context reset on error (Shaun McCance), XPath union
   2256     evaluation problem (William) , xmlReallocLoc with NULL (Aleksey Sanin),
   2257     XML Schemas double free (Steve Ball), XInclude with no href, argument
   2258     callbacks order for XPath callbacks (Frederic Peters)</li>
   2259   <li>Documentation: python scripts (William Brack), xslt stylesheets (John
   2260     Fleck), doc (Sven Zimmerman), I/O example.</li>
   2261   <li>Python bindings: fixes (William), enum support (Stphane Bidoul),
   2262     structured error reporting (Stphane Bidoul)</li>
   2263   <li>XInclude: various fixes for conformance, problem related to dictionnary
   2264     references (William &amp; me), recursion (William)</li>
   2265   <li>xmlWriter: indentation (Lucas Brasilino), memory leaks (Alfred
   2266     Mickautsch),</li>
   2267   <li>xmlSchemas: normalizedString datatype (John Belmonte)</li>
   2268   <li>code cleanup for strings functions (William)</li>
   2269   <li>Windows: compiler patches (Mark Vakoc)</li>
   2270   <li>Parser optimizations, a few new XPath and dictionnary APIs for future
   2271     XSLT optimizations.</li>
   2272 </ul>
   2273 
   2274 <h3>2.6.4: Dec 24 2003</h3>
   2275 <ul>
   2276   <li>Windows build fixes (Igor Zlatkovic)</li>
   2277   <li>Some serious XInclude problems reported by Oleg Paraschenko and</li>
   2278   <li>Unix and Makefile packaging fixes (me, William Brack,</li>
   2279   <li>Documentation improvements (John Fleck, William Brack), example fix
   2280     (Lucas Brasilino)</li>
   2281   <li>bugfixes: xmlTextReaderExpand() with xmlReaderWalker, XPath handling of
   2282     NULL strings (William Brack) , API building reader or parser from
   2283     filedescriptor should not close it, changed XPath sorting to be stable
   2284     again (William Brack), xmlGetNodePath() generating '(null)' (William
   2285     Brack), DTD validation and namespace bug (William Brack), XML Schemas
   2286     double inclusion behaviour</li>
   2287 </ul>
   2288 
   2289 <h3>2.6.3: Dec 10 2003</h3>
   2290 <ul>
   2291   <li>documentation updates and cleanup (DV, William Brack, John Fleck)</li>
   2292   <li>added a repository of examples, examples from Aleksey Sanin, Dodji
   2293     Seketeli, Alfred Mickautsch</li>
   2294   <li>Windows updates: Mark Vakoc, Igor Zlatkovic, Eric Zurcher, Mingw
   2295     (Kenneth Haley)</li>
   2296   <li>Unicode range checking (William Brack)</li>
   2297   <li>code cleanup (William Brack)</li>
   2298   <li>Python bindings: doc (John Fleck),  bug fixes</li>
   2299   <li>UTF-16 cleanup and BOM issues (William Brack)</li>
   2300   <li>bug fixes: ID and xmlReader validation, XPath (William Brack),
   2301     xmlWriter (Alfred Mickautsch), hash.h inclusion problem, HTML parser
   2302     (James Bursa), attribute defaulting and validation, some serialization
   2303     cleanups, XML_GET_LINE macro, memory debug when using threads (William
   2304     Brack), serialization of attributes and entities content, xmlWriter
   2305     (Daniel Schulman)</li>
   2306   <li>XInclude bugfix, new APIs and update to the last version including the
   2307     namespace change.</li>
   2308   <li>XML Schemas improvements: include (Robert Stepanek), import and
   2309     namespace handling, fixed the regression tests troubles, added examples
   2310     based on Eric van der Vlist book, regexp fixes</li>
   2311   <li>preliminary pattern support for streaming (needed for schemas
   2312     constraints), added xmlTextReaderPreservePattern() to collect subdocument
   2313     when streaming.</li>
   2314   <li>various fixes in the structured error handling</li>
   2315 </ul>
   2316 
   2317 <h3>2.6.2: Nov 4 2003</h3>
   2318 <ul>
   2319   <li>XPath context unregistration fixes</li>
   2320   <li>text node coalescing fixes (Mark Lilback)</li>
   2321   <li>API to screate a W3C Schemas from an existing document (Steve Ball)</li>
   2322   <li>BeOS patches (Marcin 'Shard' Konicki)</li>
   2323   <li>xmlStrVPrintf function added (Aleksey Sanin)</li>
   2324   <li>compilation fixes (Mark Vakoc)</li>
   2325   <li>stdin parsing fix (William Brack)</li>
   2326   <li>a posteriori DTD validation fixes</li>
   2327   <li>xmlReader bug fixes: Walker fixes, python bindings</li>
   2328   <li>fixed xmlStopParser() to really stop the parser and errors</li>
   2329   <li>always generate line numbers when using the new xmlReadxxx
   2330   functions</li>
   2331   <li>added XInclude support to the xmlReader interface</li>
   2332   <li>implemented XML_PARSE_NONET parser option</li>
   2333   <li>DocBook XSLT processing bug fixed</li>
   2334   <li>HTML serialization for &lt;p&gt; elements (William Brack and me)</li>
   2335   <li>XPointer failure in XInclude are now handled as resource errors</li>
   2336   <li>fixed xmllint --html to use the HTML serializer on output (added
   2337     --xmlout to implement the previous behaviour of saving it using the XML
   2338     serializer)</li>
   2339 </ul>
   2340 
   2341 <h3>2.6.1: Oct 28 2003</h3>
   2342 <ul>
   2343   <li>Mostly bugfixes after the big 2.6.0 changes</li>
   2344   <li>Unix compilation patches: libxml.m4 (Patrick Welche), warnings cleanup
   2345     (William Brack)</li>
   2346   <li>Windows compilation patches (Joachim Bauch, Stephane Bidoul, Igor
   2347     Zlatkovic)</li>
   2348   <li>xmlWriter bugfix (Alfred Mickautsch)</li>
   2349   <li>chvalid.[ch]: couple of fixes from Stephane Bidoul</li>
   2350   <li>context reset: error state reset, push parser reset (Graham
   2351   Bennett)</li>
   2352   <li>context reuse: generate errors if file is not readable</li>
   2353   <li>defaulted attributes for element coming from internal entities
   2354     (Stephane Bidoul)</li>
   2355   <li>Python: tab and spaces mix (William Brack)</li>
   2356   <li>Error handler could crash in DTD validation in 2.6.0</li>
   2357   <li>xmlReader: do not use the document or element _private field</li>
   2358   <li>testSAX.c: avoid a problem with some PIs (Massimo Morara)</li>
   2359   <li>general bug fixes: mandatory encoding in text decl, serializing
   2360     Document Fragment nodes, xmlSearchNs 2.6.0 problem (Kasimier Buchcik),
   2361     XPath errors not reported,  slow HTML parsing of large documents.</li>
   2362 </ul>
   2363 
   2364 <h3>2.6.0: Oct 20 2003</h3>
   2365 <ul>
   2366   <li>Major revision release: should be API and ABI compatible but got a lot
   2367     of change</li>
   2368   <li>Increased the library modularity, far more options can be stripped out,
   2369     a --with-minimum configuration will weight around 160KBytes</li>
   2370   <li>Use per parser and per document dictionnary, allocate names and small
   2371     text nodes from the dictionnary</li>
   2372   <li>Switch to a SAX2 like parser rewrote most of the XML parser core,
   2373     provides namespace resolution and defaulted attributes, minimize memory
   2374     allocations and copies, namespace checking and specific error handling,
   2375     immutable buffers, make predefined entities static structures, etc...</li>
   2376   <li>rewrote all the error handling in the library, all errors can be
   2377     intercepted at a structured level, with precise information
   2378   available.</li>
   2379   <li>New simpler and more generic XML and HTML parser APIs, allowing to
   2380     easilly modify the parsing options and reuse parser context for multiple
   2381     consecutive documents.</li>
   2382   <li>Similar new APIs for the xmlReader, for options and reuse, provided new
   2383     functions to access content as const strings, use them for Python
   2384   bindings</li>
   2385   <li>a  lot of other smaller API improvements: xmlStrPrintf (Aleksey Sanin),
   2386     Walker i.e. reader on a document tree based on Alfred Mickautsch code,
   2387     make room in nodes for line numbers, reference counting and future PSVI
   2388     extensions, generation of character ranges to be checked with faster
   2389     algorithm (William),  xmlParserMaxDepth (Crutcher Dunnavant), buffer
   2390     access</li>
   2391   <li>New xmlWriter API provided by Alfred Mickautsch</li>
   2392   <li>Schemas: base64 support by Anthony Carrico</li>
   2393   <li>Parser&lt;-&gt;HTTP integration fix, proper processing of the Mime-Type
   2394     and charset information if available.</li>
   2395   <li>Relax-NG: bug fixes including the one reported by Martijn Faassen and
   2396     zeroOrMore, better error reporting.</li>
   2397   <li>Python bindings (Stphane Bidoul), never use stdout for errors
   2398   output</li>
   2399   <li>Portability: all the headers have macros for export and calling
   2400     convention definitions (Igor Zlatkovic), VMS update (Craig A. Berry),
   2401     Windows: threads (Jesse Pelton), Borland compiler (Eric Zurcher,  Igor),
   2402     Mingw (Igor), typos (Mark Vakoc),  beta version (Stephane Bidoul),
   2403     warning cleanups on AIX and MIPS compilers (William Brack), BeOS (Marcin
   2404     'Shard' Konicki)</li>
   2405   <li>Documentation fixes and README (William Brack), search fix (William),
   2406     tutorial updates (John Fleck), namespace docs (Stefan Kost)</li>
   2407   <li>Bug fixes: xmlCleanupParser (Dave Beckett), threading uninitialized
   2408     mutexes, HTML doctype lowercase,  SAX/IO (William), compression detection
   2409     and restore (William), attribute declaration in DTDs (William), namespace
   2410     on attribute in HTML output (William), input filename (Rob Richards),
   2411     namespace DTD validation, xmlReplaceNode (Chris Ryland), I/O callbacks
   2412     (Markus Keim), CDATA serialization (Shaun McCance), xmlReader (Peter
   2413     Derr), high codepoint charref like &amp;#x10FFFF;, buffer access in push
   2414     mode (Justin Fletcher), TLS threads on Windows (Jesse Pelton), XPath bug
   2415     (William), xmlCleanupParser (Marc Liyanage), CDATA output (William), HTTP
   2416     error handling.</li>
   2417   <li>xmllint options: --dtdvalidfpi for Tobias Reif, --sax1 for compat
   2418     testing,  --nodict for building without tree dictionnary, --nocdata to
   2419     replace CDATA by text, --nsclean to remove surperfluous  namespace
   2420     declarations</li>
   2421   <li>added xml2-config --libtool-libs option from Kevin P. Fleming</li>
   2422   <li>a lot of profiling and tuning of the code, speedup patch for
   2423     xmlSearchNs() by Luca Padovani. The xmlReader should do far less
   2424     allocation and it speed should get closer to SAX. Chris Anderson worked
   2425     on speeding and cleaning up repetitive checking code.</li>
   2426   <li>cleanup of "make tests"</li>
   2427   <li>libxml-2.0-uninstalled.pc from Malcolm Tredinnick</li>
   2428   <li>deactivated the broken docBook SGML parser code and plugged the XML
   2429     parser instead.</li>
   2430 </ul>
   2431 
   2432 <h3>2.5.11: Sep 9 2003</h3>
   2433 
   2434 <p>A bugfix only release:</p>
   2435 <ul>
   2436   <li>risk of crash in Relax-NG</li>
   2437   <li>risk of crash when using multithreaded programs</li>
   2438 </ul>
   2439 
   2440 <h3>2.5.10: Aug 15 2003</h3>
   2441 
   2442 <p>A bugfixes only release</p>
   2443 <ul>
   2444   <li>Windows Makefiles (William Brack)</li>
   2445   <li>UTF-16 support fixes (Mark Itzcovitz)</li>
   2446   <li>Makefile and portability (William Brack) automake, Linux alpha, Mingw
   2447     on Windows (Mikhail Grushinskiy)</li>
   2448   <li>HTML parser (Oliver Stoeneberg)</li>
   2449   <li>XInclude performance problem reported by Kevin Ruscoe</li>
   2450   <li>XML parser performance problem reported by Grant Goodale</li>
   2451   <li>xmlSAXParseDTD() bug fix from Malcolm Tredinnick</li>
   2452   <li>and a couple other cleanup</li>
   2453 </ul>
   2454 
   2455 <h3>2.5.9: Aug 9 2003</h3>
   2456 <ul>
   2457   <li>bugfixes: IPv6 portability, xmlHasNsProp (Markus Keim), Windows build
   2458     (Wiliam Brake, Jesse Pelton, Igor), Schemas (Peter Sobisch), threading
   2459     (Rob Richards), hexBinary type (), UTF-16 BOM (Dodji Seketeli),
   2460     xmlReader, Relax-NG schemas compilation, namespace handling,  EXSLT (Sean
   2461     Griffin), HTML parsing problem (William Brack), DTD validation for mixed
   2462     content + namespaces, HTML serialization, library initialization,
   2463     progressive HTML parser</li>
   2464   <li>better interfaces for Relax-NG error handling (Joachim Bauch, )</li>
   2465   <li>adding xmlXIncludeProcessTree() for XInclud'ing in a subtree</li>
   2466   <li>doc fixes and improvements (John Fleck)</li>
   2467   <li>configure flag for -with-fexceptions when embedding in C++</li>
   2468   <li>couple of new UTF-8 helper functions (William Brack)</li>
   2469   <li>general encoding cleanup + ISO-8859-x without iconv (Peter Jacobi)</li>
   2470   <li>xmlTextReader cleanup + enum for node types (Bjorn Reese)</li>
   2471   <li>general compilation/warning cleanup Solaris/HP-UX/... (William
   2472   Brack)</li>
   2473 </ul>
   2474 
   2475 <h3>2.5.8: Jul 6 2003</h3>
   2476 <ul>
   2477   <li>bugfixes: XPath, XInclude, file/URI mapping, UTF-16 save (Mark
   2478     Itzcovitz), UTF-8 checking, URI saving, error printing (William Brack),
   2479     PI related memleak, compilation without schemas or without xpath (Joerg
   2480     Schmitz-Linneweber/Garry Pennington), xmlUnlinkNode problem with DTDs,
   2481     rpm problem on , i86_64, removed a few compilation problems from 2.5.7,
   2482     xmlIOParseDTD, and xmlSAXParseDTD (Malcolm Tredinnick)</li>
   2483   <li>portability: DJGPP (MsDos) , OpenVMS (Craig A. Berry)</li>
   2484   <li>William Brack fixed multithreading lock problems</li>
   2485   <li>IPv6 patch for FTP and HTTP accesses (Archana Shah/Wipro)</li>
   2486   <li>Windows fixes (Igor Zlatkovic,  Eric Zurcher), threading (Stphane
   2487     Bidoul)</li>
   2488   <li>A few W3C Schemas Structure improvements</li>
   2489   <li>W3C Schemas Datatype improvements (Charlie Bozeman)</li>
   2490   <li>Python bindings for thread globals (Stphane Bidoul), and method/class
   2491     generator</li>
   2492   <li>added --nonet option to xmllint</li>
   2493   <li>documentation improvements (John Fleck)</li>
   2494 </ul>
   2495 
   2496 <h3>2.5.7: Apr 25 2003</h3>
   2497 <ul>
   2498   <li>Relax-NG: Compiling to regexp and streaming validation on top of the
   2499     xmlReader interface, added to xmllint --stream</li>
   2500   <li>xmlReader: Expand(), Next() and DOM access glue, bug fixes</li>
   2501   <li>Support for large files: RGN validated a 4.5GB instance</li>
   2502   <li>Thread support is now configured in by default</li>
   2503   <li>Fixes: update of the Trio code (Bjorn), WXS Date and Duration fixes
   2504     (Charles Bozeman), DTD and namespaces (Brent Hendricks), HTML push parser
   2505     and zero bytes handling, some missing Windows file path conversions,
   2506     behaviour of the parser and validator in the presence of "out of memory"
   2507     error conditions</li>
   2508   <li>extended the API to be able to plug a garbage collecting memory
   2509     allocator, added xmlMallocAtomic() and modified the allocations
   2510     accordingly.</li>
   2511   <li>Performances: removed excessive malloc() calls, speedup of the push and
   2512     xmlReader interfaces, removed excessive thread locking</li>
   2513   <li>Documentation: man page (John Fleck), xmlReader documentation</li>
   2514   <li>Python: adding binding for xmlCatalogAddLocal (Brent M Hendricks)</li>
   2515 </ul>
   2516 
   2517 <h3>2.5.6: Apr 1 2003</h3>
   2518 <ul>
   2519   <li>Fixed W3C XML Schemas datatype, should be compliant now except for
   2520     binHex and base64 which are not supported yet.</li>
   2521   <li>bug fixes: non-ASCII IDs, HTML output, XInclude on large docs and
   2522     XInclude entities handling, encoding detection on external subsets, XML
   2523     Schemas bugs and memory leaks, HTML parser (James Bursa)</li>
   2524   <li>portability: python/trio (Albert Chin), Sun compiler warnings</li>
   2525   <li>documentation: added --relaxng option to xmllint man page (John)</li>
   2526   <li>improved error reporting: xml:space, start/end tag mismatches, Relax NG
   2527     errors</li>
   2528 </ul>
   2529 
   2530 <h3>2.5.5: Mar 24 2003</h3>
   2531 <ul>
   2532   <li>Lot of fixes on the Relax NG implementation. More testing including
   2533     DocBook and TEI examples.</li>
   2534   <li>Increased the support for W3C XML Schemas datatype</li>
   2535   <li>Several bug fixes in the URI handling layer</li>
   2536   <li>Bug fixes: HTML parser, xmlReader, DTD validation, XPath, encoding
   2537     conversion, line counting in the parser.</li>
   2538   <li>Added support for $XMLLINT_INDENT environment variable, FTP delete</li>
   2539   <li>Fixed the RPM spec file name</li>
   2540 </ul>
   2541 
   2542 <h3>2.5.4: Feb 20 2003</h3>
   2543 <ul>
   2544   <li>Conformance testing and lot of fixes on Relax NG and XInclude
   2545     implementation</li>
   2546   <li>Implementation of XPointer element() scheme</li>
   2547   <li>Bug fixes: XML parser, XInclude entities merge, validity checking on
   2548     namespaces,
   2549     <p>2 serialization bugs, node info generation problems, a DTD regexp
   2550     generation problem.</p>
   2551   </li>
   2552   <li>Portability: windows updates and path canonicalization (Igor)</li>
   2553   <li>A few typo fixes (Kjartan Maraas)</li>
   2554   <li>Python bindings generator fixes (Stephane Bidoul)</li>
   2555 </ul>
   2556 
   2557 <h3>2.5.3: Feb 10 2003</h3>
   2558 <ul>
   2559   <li>RelaxNG and XML Schemas datatypes improvements, and added a first
   2560     version of RelaxNG Python bindings</li>
   2561   <li>Fixes: XLink (Sean Chittenden), XInclude (Sean Chittenden), API fix for
   2562     serializing namespace nodes, encoding conversion bug, XHTML1
   2563   serialization</li>
   2564   <li>Portability fixes: Windows (Igor), AMD 64bits RPM spec file</li>
   2565 </ul>
   2566 
   2567 <h3>2.5.2: Feb 5 2003</h3>
   2568 <ul>
   2569   <li>First implementation of RelaxNG, added --relaxng flag to xmllint</li>
   2570   <li>Schemas support now compiled in by default.</li>
   2571   <li>Bug fixes: DTD validation, namespace checking, XInclude and entities,
   2572     delegateURI in XML Catalogs, HTML parser, XML reader (Stphane Bidoul),
   2573     XPath parser and evaluation,  UTF8ToUTF8 serialization, XML reader memory
   2574     consumption, HTML parser, HTML serialization in the presence of
   2575   namespaces</li>
   2576   <li>added an HTML API to check elements and attributes.</li>
   2577   <li>Documentation improvement, PDF for the tutorial (John Fleck), doc
   2578     patches (Stefan Kost)</li>
   2579   <li>Portability fixes: NetBSD (Julio Merino), Windows (Igor Zlatkovic)</li>
   2580   <li>Added python bindings for XPointer, contextual error reporting
   2581     (Stphane Bidoul)</li>
   2582   <li>URI/file escaping problems (Stefano Zacchiroli)</li>
   2583 </ul>
   2584 
   2585 <h3>2.5.1: Jan 8 2003</h3>
   2586 <ul>
   2587   <li>Fixes a memory leak and configuration/compilation problems in 2.5.0</li>
   2588   <li>documentation updates (John)</li>
   2589   <li>a couple of XmlTextReader fixes</li>
   2590 </ul>
   2591 
   2592 <h3>2.5.0: Jan 6 2003</h3>
   2593 <ul>
   2594   <li>New <a href="xmlreader.html">XmltextReader interface</a> based on C#
   2595     API (with help of Stphane Bidoul)</li>
   2596   <li>Windows: more exports, including the new API (Igor)</li>
   2597   <li>XInclude fallback fix</li>
   2598   <li>Python: bindings for the new API, packaging (Stphane Bidoul),
   2599     drv_libxml2.py Python xml.sax driver (Stphane Bidoul), fixes, speedup
   2600     and iterators for Python-2.2 (Hannu Krosing)</li>
   2601   <li>Tutorial fixes (john Fleck and Niraj Tolia) xmllint man update
   2602   (John)</li>
   2603   <li>Fix an XML parser bug raised by Vyacheslav Pindyura</li>
   2604   <li>Fix for VMS serialization (Nigel Hall) and config (Craig A. Berry)</li>
   2605   <li>Entities handling fixes</li>
   2606   <li>new API to optionally track node creation and deletion (Lukas
   2607   Schroeder)</li>
   2608   <li>Added documentation for the XmltextReader interface and some <a
   2609     href="guidelines.html">XML guidelines</a></li>
   2610 </ul>
   2611 
   2612 <h3>2.4.30: Dec 12 2002</h3>
   2613 <ul>
   2614   <li>2.4.29 broke the python bindings, rereleasing</li>
   2615   <li>Improvement/fixes of the XML API generator, and couple of minor code
   2616     fixes.</li>
   2617 </ul>
   2618 
   2619 <h3>2.4.29: Dec 11 2002</h3>
   2620 <ul>
   2621   <li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings
   2622     (Stphane Bidoul), Mingw (Magnus Henoch), and export list updates</li>
   2623   <li>Fix for prev in python bindings (ERDI Gergo)</li>
   2624   <li>Fix for entities handling (Marcus Clarke)</li>
   2625   <li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1
   2626     dump</li>
   2627   <li>Fix for URI parsing when handling URNs with fragment identifiers</li>
   2628   <li>Fix for HTTP URL escaping problem</li>
   2629   <li>added an TextXmlReader (C#) like API (work in progress)</li>
   2630   <li>Rewrote the API in XML generation script, includes a C parser and saves
   2631     more information needed for C# bindings</li>
   2632 </ul>
   2633 
   2634 <h3>2.4.28: Nov 22 2002</h3>
   2635 <ul>
   2636   <li>a couple of python binding fixes</li>
   2637   <li>2 bug fixes in the XML push parser</li>
   2638   <li>potential memory leak removed (Martin Stoilov)</li>
   2639   <li>fix to the configure script for Unix (Dimitri Papadopoulos)</li>
   2640   <li>added encoding support for XInclude parse="text"</li>
   2641   <li>autodetection of XHTML1 and specific serialization rules added</li>
   2642   <li>nasty threading bug fixed (William Brack)</li>
   2643 </ul>
   2644 
   2645 <h3>2.4.27: Nov 17 2002</h3>
   2646 <ul>
   2647   <li>fixes for the Python bindings</li>
   2648   <li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(),
   2649     HTML parser,  Schemas (Charles Bozeman), document fragment support
   2650     (Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer,
   2651     xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr
   2652     Pajas), entities processing</li>
   2653   <li>added grep to xmllint --shell</li>
   2654   <li>VMS update patch from Craig A. Berry</li>
   2655   <li>cleanup of the Windows build with support for more compilers (Igor),
   2656     better thread support on Windows</li>
   2657   <li>cleanup of Unix Makefiles and spec file</li>
   2658   <li>Improvements to the documentation (John Fleck)</li>
   2659 </ul>
   2660 
   2661 <h3>2.4.26: Oct 18 2002</h3>
   2662 <ul>
   2663   <li>Patches for Windows CE port, improvements on Windows paths handling</li>
   2664   <li>Fixes to the validation  code (DTD and Schemas), xmlNodeGetPath() ,
   2665     HTML serialization, Namespace compliance,  and a number of small
   2666   problems</li>
   2667 </ul>
   2668 
   2669 <h3>2.4.25: Sep 26 2002</h3>
   2670 <ul>
   2671   <li>A number of bug fixes: XPath, validation, Python bindings, DOM and
   2672     tree, xmlI/O,  Html</li>
   2673   <li>Serious rewrite of XInclude</li>
   2674   <li>Made XML Schemas regexp part of the default build and APIs, small fix
   2675     and improvement of the regexp core</li>
   2676   <li>Changed the validation code to reuse XML Schemas regexp APIs</li>
   2677   <li>Better handling of Windows file paths, improvement of Makefiles (Igor,
   2678     Daniel Gehriger, Mark Vakoc)</li>
   2679   <li>Improved the python I/O bindings, the tests, added resolver and regexp
   2680     APIs</li>
   2681   <li>New logos from Marc Liyanage</li>
   2682   <li>Tutorial improvements: John Fleck, Christopher Harris</li>
   2683   <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe
   2684   Merlet)</li>
   2685   <li>removal of all stderr/perror use for error reporting</li>
   2686   <li>Better error reporting: XPath and DTD validation</li>
   2687   <li>update of the trio portability layer (Bjorn Reese)</li>
   2688 </ul>
   2689 
   2690 <p><strong>2.4.24: Aug 22 2002</strong></p>
   2691 <ul>
   2692   <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li>
   2693   <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64
   2694     (fcrozat)</li>
   2695   <li>HTML &lt;style&gt; and boolean attributes serializer fixes</li>
   2696   <li>C14N improvements by Aleksey</li>
   2697   <li>doc cleanups: Rick Jones</li>
   2698   <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li>
   2699   <li>XInclude: implementation of fallback and xml:base fixup added</li>
   2700 </ul>
   2701 
   2702 <h3>2.4.23: July 6 2002</h3>
   2703 <ul>
   2704   <li>performances patches: Peter Jacobi</li>
   2705   <li>c14n fixes, testsuite and performances: Aleksey Sanin</li>
   2706   <li>added xmlDocFormatDump: Chema Celorio</li>
   2707   <li>new tutorial: John Fleck</li>
   2708   <li>new hash functions and performances: Sander Vesik, portability fix from
   2709     Peter Jacobi</li>
   2710   <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and
   2711     HTML parsers, ID lookup function</li>
   2712   <li>removal of all remaining sprintf: Aleksey Sanin</li>
   2713 </ul>
   2714 
   2715 <h3>2.4.22: May 27 2002</h3>
   2716 <ul>
   2717   <li>a number of bug fixes: configure scripts, base handling, parser, memory
   2718     usage, HTML parser, XPath, documentation (Christian Cornelssen),
   2719     indentation, URI parsing</li>
   2720   <li>Optimizations for XMLSec, fixing and making public some of the network
   2721     protocol handlers (Aleksey)</li>
   2722   <li>performance patch from Gary Pennington</li>
   2723   <li>Charles Bozeman provided date and time support for XML Schemas
   2724   datatypes</li>
   2725 </ul>
   2726 
   2727 <h3>2.4.21: Apr 29 2002</h3>
   2728 
   2729 <p>This release is both a bug fix release and also contains the early XML
   2730 Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a
   2731 href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all
   2732 interfaces are likely to change, there is huge holes, it is clearly a work in
   2733 progress and don't even think of putting this code in a production system,
   2734 it's actually not compiled in by default. The real fixes are:
   2735 </p>
   2736 
   2737 <ul>
   2738   <li>a couple of bugs or limitations introduced in 2.4.20</li>
   2739   <li>patches for Borland C++ and MSC by Igor</li>
   2740   <li>some fixes on XPath strings and conformance patches by Richard
   2741   Jinks</li>
   2742   <li>patch from Aleksey for the ExcC14N specification</li>
   2743   <li>OSF/1 bug fix by Bjorn</li>
   2744 </ul>
   2745 
   2746 <h3>2.4.20: Apr 15 2002</h3>
   2747 <ul>
   2748   <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li>
   2749   <li>XPath conformance testing by Richard Jinks</li>
   2750   <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings,
   2751     libxml.m4</li>
   2752 </ul>
   2753 
   2754 <h3>2.4.19: Mar 25 2002</h3>
   2755 <ul>
   2756   <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8
   2757     encoder</li>
   2758   <li>portability fixes in the HTTP code</li>
   2759   <li>memory allocation checks using valgrind, and profiling tests</li>
   2760   <li>revamp of the Windows build and Makefiles</li>
   2761 </ul>
   2762 
   2763 <h3>2.4.18: Mar 18 2002</h3>
   2764 <ul>
   2765   <li>bug fixes: tree, SAX, canonicalization, validation, portability,
   2766   XPath</li>
   2767   <li>removed the --with-buffer option it was becoming unmaintainable</li>
   2768   <li>serious cleanup of the Python makefiles</li>
   2769   <li>speedup patch to XPath very effective for DocBook stylesheets</li>
   2770   <li>Fixes for Windows build, cleanup of the documentation</li>
   2771 </ul>
   2772 
   2773 <h3>2.4.17: Mar 8 2002</h3>
   2774 <ul>
   2775   <li>a lot of bug fixes, including "namespace nodes have no parents in
   2776   XPath"</li>
   2777   <li>fixed/improved the Python wrappers, added more examples and more
   2778     regression tests, XPath extension functions can now return node-sets</li>
   2779   <li>added the XML Canonicalization support from Aleksey Sanin</li>
   2780 </ul>
   2781 
   2782 <h3>2.4.16: Feb 20 2002</h3>
   2783 <ul>
   2784   <li>a lot of bug fixes, most of them were triggered by the XML Testsuite
   2785     from OASIS and W3C. Compliance has been significantly improved.</li>
   2786   <li>a couple of portability fixes too.</li>
   2787 </ul>
   2788 
   2789 <h3>2.4.15: Feb 11 2002</h3>
   2790 <ul>
   2791   <li>Fixed the Makefiles, especially the python module ones</li>
   2792   <li>A few bug fixes and cleanup</li>
   2793   <li>Includes cleanup</li>
   2794 </ul>
   2795 
   2796 <h3>2.4.14: Feb 8 2002</h3>
   2797 <ul>
   2798   <li>Change of License to the <a
   2799     href="http://www.opensource.org/licenses/mit-license.html">MIT
   2800     License</a> basically for integration in XFree86 codebase, and removing
   2801     confusion around the previous dual-licensing</li>
   2802   <li>added Python bindings, beta software but should already be quite
   2803     complete</li>
   2804   <li>a large number of fixes and cleanups, especially for all tree
   2805     manipulations</li>
   2806   <li>cleanup of the headers, generation of a reference API definition in
   2807   XML</li>
   2808 </ul>
   2809 
   2810 <h3>2.4.13: Jan 14 2002</h3>
   2811 <ul>
   2812   <li>update of the documentation: John Fleck and Charlie Bozeman</li>
   2813   <li>cleanup of timing code from Justin Fletcher</li>
   2814   <li>fixes for Windows and initial thread support on Win32: Igor and Serguei
   2815     Narojnyi</li>
   2816   <li>Cygwin patch from Robert Collins</li>
   2817   <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li>
   2818 </ul>
   2819 
   2820 <h3>2.4.12: Dec 7 2001</h3>
   2821 <ul>
   2822   <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman),
   2823     XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups
   2824   (robert)</li>
   2825   <li>Eric Lavigne contributed project files for MacOS</li>
   2826   <li>some makefiles cleanups</li>
   2827 </ul>
   2828 
   2829 <h3>2.4.11: Nov 26 2001</h3>
   2830 <ul>
   2831   <li>fixed a couple of errors in the includes, fixed a few bugs, some code
   2832     cleanups</li>
   2833   <li>xmllint man pages improvement by Heiko Rupp</li>
   2834   <li>updated VMS build instructions from John A Fotheringham</li>
   2835   <li>Windows Makefiles updates from Igor</li>
   2836 </ul>
   2837 
   2838 <h3>2.4.10: Nov 10 2001</h3>
   2839 <ul>
   2840   <li>URI escaping fix (Joel Young)</li>
   2841   <li>added xmlGetNodePath() (for paths or XPointers generation)</li>
   2842   <li>Fixes namespace handling problems when using DTD and validation</li>
   2843   <li>improvements on xmllint: Morus Walter patches for --format and
   2844     --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li>
   2845   <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li>
   2846   <li>fixes to the HTML parser</li>
   2847 </ul>
   2848 
   2849 <h3>2.4.9: Nov 6 2001</h3>
   2850 <ul>
   2851   <li>fixes more catalog bugs</li>
   2852   <li>avoid a compilation problem, improve xmlGetLineNo()</li>
   2853 </ul>
   2854 
   2855 <h3>2.4.8: Nov 4 2001</h3>
   2856 <ul>
   2857   <li>fixed SGML catalogs broken in previous release, updated xmlcatalog
   2858   tool</li>
   2859   <li>fixed a compile errors and some includes troubles.</li>
   2860 </ul>
   2861 
   2862 <h3>2.4.7: Oct 30 2001</h3>
   2863 <ul>
   2864   <li>exported some debugging interfaces</li>
   2865   <li>serious rewrite of the catalog code</li>
   2866   <li>integrated Gary Pennington thread safety patch, added configure option
   2867     and regression tests</li>
   2868   <li>removed an HTML parser bug</li>
   2869   <li>fixed a couple of potentially serious validation bugs</li>
   2870   <li>integrated the SGML DocBook support in xmllint</li>
   2871   <li>changed the nanoftp anonymous login passwd</li>
   2872   <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li>
   2873   <li>general bug fixes</li>
   2874   <li>updated xmllint man page by John Fleck</li>
   2875   <li>some VMS and Windows updates</li>
   2876 </ul>
   2877 
   2878 <h3>2.4.6: Oct 10 2001</h3>
   2879 <ul>
   2880   <li>added an updated man pages by John Fleck</li>
   2881   <li>portability and configure fixes</li>
   2882   <li>an infinite loop on the HTML parser was removed (William)</li>
   2883   <li>Windows makefile patches from Igor</li>
   2884   <li>fixed half a dozen bugs reported for libxml or libxslt</li>
   2885   <li>updated xmlcatalog to be able to modify SGML super catalogs</li>
   2886 </ul>
   2887 
   2888 <h3>2.4.5: Sep 14 2001</h3>
   2889 <ul>
   2890   <li>Remove a few annoying bugs in 2.4.4</li>
   2891   <li>forces the HTML serializer to output decimal charrefs since some
   2892     version of Netscape can't handle hexadecimal ones</li>
   2893 </ul>
   2894 
   2895 <h3>1.8.16: Sep 14 2001</h3>
   2896 <ul>
   2897   <li>maintenance release of the old libxml1 branch, couple of bug and
   2898     portability fixes</li>
   2899 </ul>
   2900 
   2901 <h3>2.4.4: Sep 12 2001</h3>
   2902 <ul>
   2903   <li>added --convert to xmlcatalog, bug fixes and cleanups of XML
   2904   Catalog</li>
   2905   <li>a few bug fixes and some portability changes</li>
   2906   <li>some documentation cleanups</li>
   2907 </ul>
   2908 
   2909 <h3>2.4.3:  Aug 23 2001</h3>
   2910 <ul>
   2911   <li>XML Catalog support see the doc</li>
   2912   <li>New NaN/Infinity floating point code</li>
   2913   <li>A few bug fixes</li>
   2914 </ul>
   2915 
   2916 <h3>2.4.2:  Aug 15 2001</h3>
   2917 <ul>
   2918   <li>adds xmlLineNumbersDefault() to control line number generation</li>
   2919   <li>lot of bug fixes</li>
   2920   <li>the Microsoft MSC projects files should now be up to date</li>
   2921   <li>inheritance of namespaces from DTD defaulted attributes</li>
   2922   <li>fixes a serious potential security bug</li>
   2923   <li>added a --format option to xmllint</li>
   2924 </ul>
   2925 
   2926 <h3>2.4.1:  July 24 2001</h3>
   2927 <ul>
   2928   <li>possibility to keep line numbers in the tree</li>
   2929   <li>some computation NaN fixes</li>
   2930   <li>extension of the XPath API</li>
   2931   <li>cleanup for alpha and ia64 targets</li>
   2932   <li>patch to allow saving through HTTP PUT or POST</li>
   2933 </ul>
   2934 
   2935 <h3>2.4.0: July 10 2001</h3>
   2936 <ul>
   2937   <li>Fixed a few bugs in XPath, validation, and tree handling.</li>
   2938   <li>Fixed XML Base implementation, added a couple of examples to the
   2939     regression tests</li>
   2940   <li>A bit of cleanup</li>
   2941 </ul>
   2942 
   2943 <h3>2.3.14: July 5 2001</h3>
   2944 <ul>
   2945   <li>fixed some entities problems and reduce memory requirement when
   2946     substituting them</li>
   2947   <li>lots of improvements in the XPath queries interpreter can be
   2948     substantially faster</li>
   2949   <li>Makefiles and configure cleanups</li>
   2950   <li>Fixes to XPath variable eval, and compare on empty node set</li>
   2951   <li>HTML tag closing bug fixed</li>
   2952   <li>Fixed an URI reference computation problem when validating</li>
   2953 </ul>
   2954 
   2955 <h3>2.3.13: June 28 2001</h3>
   2956 <ul>
   2957   <li>2.3.12 configure.in was broken as well as the push mode XML parser</li>
   2958   <li>a few more fixes for compilation on Windows MSC by Yon Derek</li>
   2959 </ul>
   2960 
   2961 <h3>1.8.14: June 28 2001</h3>
   2962 <ul>
   2963   <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li>
   2964   <li>Small Makefile fix</li>
   2965 </ul>
   2966 
   2967 <h3>2.3.12: June 26 2001</h3>
   2968 <ul>
   2969   <li>lots of cleanup</li>
   2970   <li>a couple of validation fix</li>
   2971   <li>fixed line number counting</li>
   2972   <li>fixed serious problems in the XInclude processing</li>
   2973   <li>added support for UTF8 BOM at beginning of entities</li>
   2974   <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0
   2975     miscompile uri.c (William), Thomas Leitner provided a fix for the
   2976     optimizer on Tru64</li>
   2977   <li>incorporated Yon Derek and Igor Zlatkovic  fixes and improvements for
   2978     compilation on Windows MSC</li>
   2979   <li>update of libxml-doc.el (Felix Natter)</li>
   2980   <li>fixed 2 bugs in URI normalization code</li>
   2981 </ul>
   2982 
   2983 <h3>2.3.11: June 17 2001</h3>
   2984 <ul>
   2985   <li>updates to trio, Makefiles and configure should fix some portability
   2986     problems (alpha)</li>
   2987   <li>fixed some HTML serialization problems (pre, script, and block/inline
   2988     handling), added encoding aware APIs, cleanup of this code</li>
   2989   <li>added xmlHasNsProp()</li>
   2990   <li>implemented a specific PI for encoding support in the DocBook SGML
   2991     parser</li>
   2992   <li>some XPath fixes (-Infinity, / as a function parameter and namespaces
   2993     node selection)</li>
   2994   <li>fixed a performance problem and an error in the validation code</li>
   2995   <li>fixed XInclude routine to implement the recursive behaviour</li>
   2996   <li>fixed xmlFreeNode problem when libxml is included statically twice</li>
   2997   <li>added --version to xmllint for bug reports</li>
   2998 </ul>
   2999 
   3000 <h3>2.3.10: June 1 2001</h3>
   3001 <ul>
   3002   <li>fixed the SGML catalog support</li>
   3003   <li>a number of reported bugs got fixed, in XPath, iconv detection,
   3004     XInclude processing</li>
   3005   <li>XPath string function should now handle unicode correctly</li>
   3006 </ul>
   3007 
   3008 <h3>2.3.9: May 19 2001</h3>
   3009 
   3010 <p>Lots of bugfixes, and added a basic SGML catalog support:
   3011 </p>
   3012 <ul>
   3013   <li>HTML push bugfix #54891 and another patch from Jonas Borgstrom</li>
   3014   <li>some serious speed optimization again</li>
   3015   <li>some documentation cleanups</li>
   3016   <li>trying to get better linking on Solaris (-R)</li>
   3017   <li>XPath API cleanup from Thomas Broyer</li>
   3018   <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed
   3019     xmlValidGetValidElements()</li>
   3020   <li>Added an INSTALL file</li>
   3021   <li>Attribute removal added to API: #54433</li>
   3022   <li>added a basic support for SGML catalogs</li>
   3023   <li>fixed xmlKeepBlanksDefault(0) API</li>
   3024   <li>bugfix in xmlNodeGetLang()</li>
   3025   <li>fixed a small configure portability problem</li>
   3026   <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li>
   3027 </ul>
   3028 
   3029 <h3>1.8.13: May 14 2001</h3>
   3030 <ul>
   3031   <li>bugfixes release of the old libxml1 branch used by Gnome</li>
   3032 </ul>
   3033 
   3034 <h3>2.3.8: May 3 2001</h3>
   3035 <ul>
   3036   <li>Integrated an SGML DocBook parser for the Gnome project</li>
   3037   <li>Fixed a few things in the HTML parser</li>
   3038   <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating
   3039     point portability issue</li>
   3040   <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for
   3041     DOM+validation using the XML REC as input and a 700MHz celeron).</li>
   3042   <li>incorporated more Windows cleanup</li>
   3043   <li>added xmlSaveFormatFile()</li>
   3044   <li>fixed problems in copying nodes with entities references (gdome)</li>
   3045   <li>removed some troubles surrounding the new validation module</li>
   3046 </ul>
   3047 
   3048 <h3>2.3.7: April 22 2001</h3>
   3049 <ul>
   3050   <li>lots of small bug fixes, corrected XPointer</li>
   3051   <li>Non deterministic content model validation support</li>
   3052   <li>added xmlDocCopyNode for gdome2</li>
   3053   <li>revamped the way the HTML parser handles end of tags</li>
   3054   <li>XPath: corrections of namespaces support and number formatting</li>
   3055   <li>Windows: Igor Zlatkovic patches for MSC compilation</li>
   3056   <li>HTML output fixes from P C Chow and William M. Brack</li>
   3057   <li>Improved validation speed sensible for DocBook</li>
   3058   <li>fixed a big bug with ID declared in external parsed entities</li>
   3059   <li>portability fixes, update of Trio from Bjorn Reese</li>
   3060 </ul>
   3061 
   3062 <h3>2.3.6: April 8 2001</h3>
   3063 <ul>
   3064   <li>Code cleanup using extreme gcc compiler warning options, found and
   3065     cleared half a dozen potential problem</li>
   3066   <li>the Eazel team found an XML parser bug</li>
   3067   <li>cleaned up the user of some of the string formatting function. used the
   3068     trio library code to provide the one needed when the platform is missing
   3069     them</li>
   3070   <li>xpath: removed a memory leak and fixed the predicate evaluation
   3071     problem, extended the testsuite and cleaned up the result. XPointer seems
   3072     broken ...</li>
   3073 </ul>
   3074 
   3075 <h3>2.3.5: Mar 23 2001</h3>
   3076 <ul>
   3077   <li>Biggest change is separate parsing and evaluation of XPath expressions,
   3078     there is some new APIs for this too</li>
   3079   <li>included a number of bug fixes(XML push parser, 51876, notations,
   3080   52299)</li>
   3081   <li>Fixed some portability issues</li>
   3082 </ul>
   3083 
   3084 <h3>2.3.4: Mar 10 2001</h3>
   3085 <ul>
   3086   <li>Fixed bugs #51860 and #51861</li>
   3087   <li>Added a global variable xmlDefaultBufferSize to allow default buffer
   3088     size to be application tunable.</li>
   3089   <li>Some cleanup in the validation code, still a bug left and this part
   3090     should probably be rewritten to support ambiguous content model :-\</li>
   3091   <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3
   3092     parser</li>
   3093   <li>Fixed another bug in xmlNodeGetContent()</li>
   3094   <li>Bjorn fixed XPath node collection and Number formatting</li>
   3095   <li>Fixed a loop reported in the HTML parsing</li>
   3096   <li>blank space are reported even if the Dtd content model proves that they
   3097     are formatting spaces, this is for XML conformance</li>
   3098 </ul>
   3099 
   3100 <h3>2.3.3: Mar 1 2001</h3>
   3101 <ul>
   3102   <li>small change in XPath for XSLT</li>
   3103   <li>documentation cleanups</li>
   3104   <li>fix in validation by Gary Pennington</li>
   3105   <li>serious parsing performances improvements</li>
   3106 </ul>
   3107 
   3108 <h3>2.3.2: Feb 24 2001</h3>
   3109 <ul>
   3110   <li>chasing XPath bugs, found a bunch, completed some TODO</li>
   3111   <li>fixed a Dtd parsing bug</li>
   3112   <li>fixed a bug in xmlNodeGetContent</li>
   3113   <li>ID/IDREF support partly rewritten by Gary Pennington</li>
   3114 </ul>
   3115 
   3116 <h3>2.3.1: Feb 15 2001</h3>
   3117 <ul>
   3118   <li>some XPath and HTML bug fixes for XSLT</li>
   3119   <li>small extension of the hash table interfaces for DOM gdome2
   3120     implementation</li>
   3121   <li>A few bug fixes</li>
   3122 </ul>
   3123 
   3124 <h3>2.3.0: Feb 8 2001 (2.2.12 was on 25 Jan but I didn't kept track)</h3>
   3125 <ul>
   3126   <li>Lots of XPath bug fixes</li>
   3127   <li>Add a mode with Dtd lookup but without validation error reporting for
   3128     XSLT</li>
   3129   <li>Add support for text node without escaping (XSLT)</li>
   3130   <li>bug fixes for xmlCheckFilename</li>
   3131   <li>validation code bug fixes from Gary Pennington</li>
   3132   <li>Patch from Paul D. Smith correcting URI path normalization</li>
   3133   <li>Patch to allow simultaneous install of libxml-devel and
   3134   libxml2-devel</li>
   3135   <li>the example Makefile is now fixed</li>
   3136   <li>added HTML to the RPM packages</li>
   3137   <li>tree copying bugfixes</li>
   3138   <li>updates to Windows makefiles</li>
   3139   <li>optimization patch from Bjorn Reese</li>
   3140 </ul>
   3141 
   3142 <h3>2.2.11: Jan 4 2001</h3>
   3143 <ul>
   3144   <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li>
   3145   <li>added htmlHandleOmittedElem()</li>
   3146   <li>Applied Bjorn Reese's IPV6 first patch</li>
   3147   <li>Applied Paul D. Smith patches for validation of XInclude results</li>
   3148   <li>added XPointer xmlns() new scheme support</li>
   3149 </ul>
   3150 
   3151 <h3>2.2.10: Nov 25 2000</h3>
   3152 <ul>
   3153   <li>Fix the Windows problems of 2.2.8</li>
   3154   <li>integrate OpenVMS patches</li>
   3155   <li>better handling of some nasty HTML input</li>
   3156   <li>Improved the XPointer implementation</li>
   3157   <li>integrate a number of provided patches</li>
   3158 </ul>
   3159 
   3160 <h3>2.2.9: Nov 25 2000</h3>
   3161 <ul>
   3162   <li>erroneous release :-(</li>
   3163 </ul>
   3164 
   3165 <h3>2.2.8: Nov 13 2000</h3>
   3166 <ul>
   3167   <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a>
   3168     support</li>
   3169   <li>Patch in conditional section handling</li>
   3170   <li>updated MS compiler project</li>
   3171   <li>fixed some XPath problems</li>
   3172   <li>added an URI escaping function</li>
   3173   <li>some other bug fixes</li>
   3174 </ul>
   3175 
   3176 <h3>2.2.7: Oct 31 2000</h3>
   3177 <ul>
   3178   <li>added message redirection</li>
   3179   <li>XPath improvements (thanks TOM !)</li>
   3180   <li>xmlIOParseDTD() added</li>
   3181   <li>various small fixes in the HTML, URI, HTTP and XPointer support</li>
   3182   <li>some cleanup of the Makefile, autoconf and the distribution content</li>
   3183 </ul>
   3184 
   3185 <h3>2.2.6: Oct 25 2000:</h3>
   3186 <ul>
   3187   <li>Added an hash table module, migrated a number of internal structure to
   3188     those</li>
   3189   <li>Fixed a posteriori validation problems</li>
   3190   <li>HTTP module cleanups</li>
   3191   <li>HTML parser improvements (tag errors, script/style handling, attribute
   3192     normalization)</li>
   3193   <li>coalescing of adjacent text nodes</li>
   3194   <li>couple of XPath bug fixes, exported the internal API</li>
   3195 </ul>
   3196 
   3197 <h3>2.2.5: Oct 15 2000:</h3>
   3198 <ul>
   3199   <li>XPointer implementation and testsuite</li>
   3200   <li>Lot of XPath fixes, added variable and functions registration, more
   3201     tests</li>
   3202   <li>Portability fixes, lots of enhancements toward an easy Windows build
   3203     and release</li>
   3204   <li>Late validation fixes</li>
   3205   <li>Integrated a lot of contributed patches</li>
   3206   <li>added memory management docs</li>
   3207   <li>a performance problem when using large buffer seems fixed</li>
   3208 </ul>
   3209 
   3210 <h3>2.2.4: Oct 1 2000:</h3>
   3211 <ul>
   3212   <li>main XPath problem fixed</li>
   3213   <li>Integrated portability patches for Windows</li>
   3214   <li>Serious bug fixes on the URI and HTML code</li>
   3215 </ul>
   3216 
   3217 <h3>2.2.3: Sep 17 2000</h3>
   3218 <ul>
   3219   <li>bug fixes</li>
   3220   <li>cleanup of entity handling code</li>
   3221   <li>overall review of all loops in the parsers, all sprintf usage has been
   3222     checked too</li>
   3223   <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd
   3224     works smoothly now.</li>
   3225 </ul>
   3226 
   3227 <h3>1.8.10: Sep 6 2000</h3>
   3228 <ul>
   3229   <li>bug fix release for some Gnome projects</li>
   3230 </ul>
   3231 
   3232 <h3>2.2.2: August 12 2000</h3>
   3233 <ul>
   3234   <li>mostly bug fixes</li>
   3235   <li>started adding routines to access xml parser context options</li>
   3236 </ul>
   3237 
   3238 <h3>2.2.1: July 21 2000</h3>
   3239 <ul>
   3240   <li>a purely bug fixes release</li>
   3241   <li>fixed an encoding support problem when parsing from a memory block</li>
   3242   <li>fixed a DOCTYPE parsing problem</li>
   3243   <li>removed a bug in the function allowing to override the memory
   3244     allocation routines</li>
   3245 </ul>
   3246 
   3247 <h3>2.2.0: July 14 2000</h3>
   3248 <ul>
   3249   <li>applied a lot of portability fixes</li>
   3250   <li>better encoding support/cleanup and saving (content is now always
   3251     encoded in UTF-8)</li>
   3252   <li>the HTML parser now correctly handles encodings</li>
   3253   <li>added xmlHasProp()</li>
   3254   <li>fixed a serious problem with &amp;#38;</li>
   3255   <li>propagated the fix to FTP client</li>
   3256   <li>cleanup, bugfixes, etc ...</li>
   3257   <li>Added a page about <a href="encoding.html">libxml Internationalization
   3258     support</a></li>
   3259 </ul>
   3260 
   3261 <h3>1.8.9:  July 9 2000</h3>
   3262 <ul>
   3263   <li>fixed the spec the RPMs should be better</li>
   3264   <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve
   3265     rpmfind users problem</li>
   3266 </ul>
   3267 
   3268 <h3>2.1.1: July 1 2000</h3>
   3269 <ul>
   3270   <li>fixes a couple of bugs in the 2.1.0 packaging</li>
   3271   <li>improvements on the HTML parser</li>
   3272 </ul>
   3273 
   3274 <h3>2.1.0 and 1.8.8: June 29 2000</h3>
   3275 <ul>
   3276   <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according
   3277     to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem
   3278     about &amp;#38; charref parsing</li>
   3279   <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it
   3280     also contains numerous fixes and enhancements:
   3281     <ul>
   3282       <li>added xmlStopParser() to stop parsing</li>
   3283       <li>improved a lot parsing speed when there is large CDATA blocs</li>
   3284       <li>includes XPath patches provided by Picdar Technology</li>
   3285       <li>tried to fix as much as possible DTD validation and namespace
   3286         related problems</li>
   3287       <li>output to a given encoding has been added/tested</li>
   3288       <li>lot of various fixes</li>
   3289     </ul>
   3290   </li>
   3291 </ul>
   3292 
   3293 <h3>2.0.0: Apr 12 2000</h3>
   3294 <ul>
   3295   <li>First public release of libxml2. If you are using libxml, it's a good
   3296     idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially
   3297     scheduled for Apr 3 the release occurred only on Apr 12 due to massive
   3298     workload.</li>
   3299   <li>The include are now located under $prefix/include/libxml (instead of
   3300     $prefix/include/gnome-xml), they also are referenced by
   3301     <pre>#include &lt;libxml/xxx.h&gt;</pre>
   3302     <p>instead of</p>
   3303     <pre>#include "xxx.h"</pre>
   3304   </li>
   3305   <li>a new URI module for parsing URIs and following strictly RFC 2396</li>
   3306   <li>the memory allocation routines used by libxml can now be overloaded
   3307     dynamically by using xmlMemSetup()</li>
   3308   <li>The previously CVS only tool tester has been renamed
   3309     <strong>xmllint</strong> and is now installed as part of the libxml2
   3310     package</li>
   3311   <li>The I/O interface has been revamped. There is now ways to plug in
   3312     specific I/O modules, either at the URI scheme detection level using
   3313     xmlRegisterInputCallbacks()  or by passing I/O functions when creating a
   3314     parser context using xmlCreateIOParserCtxt()</li>
   3315   <li>there is a C preprocessor macro LIBXML_VERSION providing the version
   3316     number of the libxml module in use</li>
   3317   <li>a number of optional features of libxml can now be excluded at
   3318     configure time (FTP/HTTP/HTML/XPath/Debug)</li>
   3319 </ul>
   3320 
   3321 <h3>2.0.0beta: Mar 14 2000</h3>
   3322 <ul>
   3323   <li>This is a first Beta release of libxml version 2</li>
   3324   <li>It's available only from<a href="ftp://xmlsoft.org/libxml2/">xmlsoft.org
   3325     FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and
   3326   RPMs</li>
   3327   <li>This version is now the head in the Gnome CVS base, the old one is
   3328     available under the tag LIB_XML_1_X</li>
   3329   <li>This includes a very large set of changes. From a  programmatic point
   3330     of view applications should not have to be modified too much, check the
   3331     <a href="upgrade.html">upgrade page</a></li>
   3332   <li>Some interfaces may changes (especially a bit about encoding).</li>
   3333   <li>the updates includes:
   3334     <ul>
   3335       <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly
   3336         handled now</li>
   3337       <li>Better handling of entities, especially well-formedness checking
   3338         and proper PEref extensions in external subsets</li>
   3339       <li>DTD conditional sections</li>
   3340       <li>Validation now correctly handle entities content</li>
   3341       <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change
   3342         structures to accommodate DOM</a></li>
   3343     </ul>
   3344   </li>
   3345   <li>Serious progress were made toward compliance, <a
   3346     href="conf/result.html">here are the result of the test</a> against the
   3347     OASIS testsuite (except the Japanese tests since I don't support that
   3348     encoding yet). This URL is rebuilt every couple of hours using the CVS
   3349     head version.</li>
   3350 </ul>
   3351 
   3352 <h3>1.8.7: Mar 6 2000</h3>
   3353 <ul>
   3354   <li>This is a bug fix release:</li>
   3355   <li>It is possible to disable the ignorable blanks heuristic used by
   3356     libxml-1.x, a new function  xmlKeepBlanksDefault(0) will allow this. Note
   3357     that for adherence to XML spec, this behaviour will be disabled by
   3358     default in 2.x . The same function will allow to keep compatibility for
   3359     old code.</li>
   3360   <li>Blanks in &lt;a&gt;  &lt;/a&gt; constructs are not ignored anymore,
   3361     avoiding heuristic is really the Right Way :-\</li>
   3362   <li>The unchecked use of snprintf which was breaking libxml-1.8.6
   3363     compilation on some platforms has been fixed</li>
   3364   <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing
   3365   URIs</li>
   3366 </ul>
   3367 
   3368 <h3>1.8.6: Jan 31 2000</h3>
   3369 <ul>
   3370   <li>added a nanoFTP transport module, debugged until the new version of <a
   3371     href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use
   3372     it without troubles</li>
   3373 </ul>
   3374 
   3375 <h3>1.8.5: Jan 21 2000</h3>
   3376 <ul>
   3377   <li>adding APIs to parse a well balanced chunk of XML (production <a
   3378     href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the
   3379     XML spec)</li>
   3380   <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus (a] fast.no</li>
   3381   <li>Jody Goldberg &lt;jgoldberg (a] home.com&gt; provided another patch trying
   3382     to solve the zlib checks problems</li>
   3383   <li>The current state in gnome CVS base is expected to ship as 1.8.5 with
   3384     gnumeric soon</li>
   3385 </ul>
   3386 
   3387 <h3>1.8.4: Jan 13 2000</h3>
   3388 <ul>
   3389   <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li>
   3390   <li>all exit() call should have been removed from libxml</li>
   3391   <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li>
   3392   <li>added newDocFragment()</li>
   3393 </ul>
   3394 
   3395 <h3>1.8.3: Jan 5 2000</h3>
   3396 <ul>
   3397   <li>a Push interface for the XML and HTML parsers</li>
   3398   <li>a shell-like interface to the document tree (try tester --shell :-)</li>
   3399   <li>lots of bug fixes and improvement added over XMas holidays</li>
   3400   <li>fixed the DTD parsing code to work with the xhtml DTD</li>
   3401   <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li>
   3402   <li>Fixed bugs in xmlNewNs()</li>
   3403   <li>External entity loading code has been revamped, now it uses
   3404     xmlLoadExternalEntity(), some fix on entities processing were added</li>
   3405   <li>cleaned up WIN32 includes of socket stuff</li>
   3406 </ul>
   3407 
   3408 <h3>1.8.2: Dec 21 1999</h3>
   3409 <ul>
   3410   <li>I got another problem with includes and C++, I hope this issue is fixed
   3411     for good this time</li>
   3412   <li>Added a few tree modification functions: xmlReplaceNode,
   3413     xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and
   3414     xmlDocSetRootElement</li>
   3415   <li>Tried to improve the HTML output with help from <a
   3416     href="mailto:clahey (a] umich.edu">Chris Lahey</a></li>
   3417 </ul>
   3418 
   3419 <h3>1.8.1: Dec 18 1999</h3>
   3420 <ul>
   3421   <li>various patches to avoid troubles when using libxml with C++ compilers
   3422     the "namespace" keyword and C escaping in include files</li>
   3423   <li>a problem in one of the core macros IS_CHAR was corrected</li>
   3424   <li>fixed a bug introduced in 1.8.0 breaking default namespace processing,
   3425     and more specifically the Dia application</li>
   3426   <li>fixed a posteriori validation (validation after parsing, or by using a
   3427     Dtd not specified in the original document)</li>
   3428   <li>fixed a bug in</li>
   3429 </ul>
   3430 
   3431 <h3>1.8.0: Dec 12 1999</h3>
   3432 <ul>
   3433   <li>cleanup, especially memory wise</li>
   3434   <li>the parser should be more reliable, especially the HTML one, it should
   3435     not crash, whatever the input !</li>
   3436   <li>Integrated various patches, especially a speedup improvement for large
   3437     dataset from <a href="mailto:cnygard (a] bellatlantic.net">Carl Nygard</a>,
   3438     configure with --with-buffers to enable them.</li>
   3439   <li>attribute normalization, oops should have been added long ago !</li>
   3440   <li>attributes defaulted from DTDs should be available, xmlSetProp() now
   3441     does entities escaping by default.</li>
   3442 </ul>
   3443 
   3444 <h3>1.7.4: Oct 25 1999</h3>
   3445 <ul>
   3446   <li>Lots of HTML improvement</li>
   3447   <li>Fixed some errors when saving both XML and HTML</li>
   3448   <li>More examples, the regression tests should now look clean</li>
   3449   <li>Fixed a bug with contiguous charref</li>
   3450 </ul>
   3451 
   3452 <h3>1.7.3: Sep 29 1999</h3>
   3453 <ul>
   3454   <li>portability problems fixed</li>
   3455   <li>snprintf was used unconditionally, leading to link problems on system
   3456     were it's not available, fixed</li>
   3457 </ul>
   3458 
   3459 <h3>1.7.1: Sep 24 1999</h3>
   3460 <ul>
   3461   <li>The basic type for strings manipulated by libxml has been renamed in
   3462     1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason
   3463     is that CHAR was conflicting with a predefined type on Windows. However
   3464     on non WIN32 environment, compatibility is provided by the way of  a
   3465     <strong>#define </strong>.</li>
   3466   <li>Changed another error : the use of a structure field called errno, and
   3467     leading to troubles on platforms where it's a macro</li>
   3468 </ul>
   3469 
   3470 <h3>1.7.0: Sep 23 1999</h3>
   3471 <ul>
   3472   <li>Added the ability to fetch remote DTD or parsed entities, see the <a
   3473     href="html/libxml-nanohttp.html">nanohttp</a> module.</li>
   3474   <li>Added an errno to report errors by another mean than a simple printf
   3475     like callback</li>
   3476   <li>Finished ID/IDREF support and checking when validation</li>
   3477   <li>Serious memory leaks fixed (there is now a <a
   3478     href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li>
   3479   <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a>
   3480     implementation</li>
   3481   <li>Added an HTML parser front-end</li>
   3482 </ul>
   3483 
   3484 <h2><a name="XML">XML</a></h2>
   3485 
   3486 <p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for
   3487 markup-based structured documents. Here is <a name="example">an example XML
   3488 document</a>:</p>
   3489 <pre>&lt;?xml version="1.0"?&gt;
   3490 &lt;EXAMPLE prop1="gnome is great" prop2="&amp;amp; linux too"&gt;
   3491   &lt;head&gt;
   3492    &lt;title&gt;Welcome to Gnome&lt;/title&gt;
   3493   &lt;/head&gt;
   3494   &lt;chapter&gt;
   3495    &lt;title&gt;The Linux adventure&lt;/title&gt;
   3496    &lt;p&gt;bla bla bla ...&lt;/p&gt;
   3497    &lt;image href="linus.gif"/&gt;
   3498    &lt;p&gt;...&lt;/p&gt;
   3499   &lt;/chapter&gt;
   3500 &lt;/EXAMPLE&gt;</pre>
   3501 
   3502 <p>The first line specifies that it is an XML document and gives useful
   3503 information about its encoding.  Then the rest of the document is a text
   3504 format whose structure is specified by tags between brackets. <strong>Each
   3505 tag opened has to be closed</strong>. XML is pedantic about this. However, if
   3506 a tag is empty (no content), a single tag can serve as both the opening and
   3507 closing tag if it ends with <code>/&gt;</code> rather than with
   3508 <code>&gt;</code>. Note that, for example, the image tag has no content (just
   3509 an attribute) and is closed by ending the tag with <code>/&gt;</code>.</p>
   3510 
   3511 <p>XML can be applied successfully to a wide range of tasks, ranging from
   3512 long term structured document maintenance (where it follows the steps of
   3513 SGML) to simple data encoding mechanisms like configuration file formatting
   3514 (glade), spreadsheets (gnumeric), or even shorter lived documents such as
   3515 WebDAV where it is used to encode remote calls between a client and a
   3516 server.</p>
   3517 
   3518 <h2><a name="XSLT">XSLT</a></h2>
   3519 
   3520 <p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p>
   3521 
   3522 <p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>,  is a
   3523 language for transforming XML documents into other XML documents (or
   3524 HTML/textual output).</p>
   3525 
   3526 <p>A separate library called libxslt is available implementing XSLT-1.0 for
   3527 libxml2. This module "libxslt" too can be found in the Gnome SVN base.</p>
   3528 
   3529 <p>You can check the progresses on the libxslt <a
   3530 href="http://xmlsoft.org/XSLT/ChangeLog.html">Changelog</a>.</p>
   3531 
   3532 <h2><a name="Python">Python and bindings</a></h2>
   3533 
   3534 <p>There are a number of language bindings and wrappers available for
   3535 libxml2, the list below is not exhaustive. Please contact the <a
   3536 href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings (a] gnome.org</a>
   3537 (<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in
   3538 order to get updates to this list or to discuss the specific topic of libxml2
   3539 or libxslt wrappers or bindings:</p>
   3540 <ul>
   3541   <li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the
   3542     most up-to-date C++ bindings for libxml2, check the <a
   3543     href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a>
   3544     and the <a
   3545     href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li>
   3546   <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper
   3547     based on the gdome2 bindings</a> maintained by Tobias Peters.</li>
   3548   <li>and a third C++ wrapper by Peter Jones &lt;pjones (a] pmade.org&gt;
   3549     <p>Website: <a
   3550     href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p>
   3551   </li>
   3552   <li>XML::LibXML <a href="http://cpan.uwinnipeg.ca/dist/XML-LibXML">Perl
   3553       bindings</a> are available on CPAN, as well as XML::LibXSLT
   3554       <a href="http://cpan.uwinnipeg.ca/dist/XML-LibXSLT">Perl libxslt
   3555       bindings</a>.</li>
   3556   <li>If you're interested into scripting XML processing, have a look at <a
   3557     href="http://xsh.sourceforge.net/">XSH</a> an XML editing shell based on
   3558     Libxml2 Perl bindings.</li>
   3559   <li><a href="mailto:dkuhlman (a] cutter.rexx.com">Dave Kuhlman</a> provides an
   3560     earlier version of the libxml/libxslt <a
   3561     href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li>
   3562   <li>Gopal.V and Peter Minten develop <a
   3563     href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of
   3564     C# libxml2 bindings.</li>
   3565   <li>Petr Kozelka provides <a
   3566     href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
   3567     libxml2</a> with Kylix, Delphi and other Pascal compilers.</li>
   3568   <li>Uwe Fechner also provides <a
   3569     href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2
   3570     implementation for Kylix2/D5/D6 from Borland.</li>
   3571   <li>There is <a href="http://libxml.rubyforge.org/">bindings for Ruby</a> 
   3572     and libxml2 bindings are also available in Ruby through the <a
   3573     href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module
   3574     maintained by Tobias Peters.</li>
   3575   <li>Steve Ball and contributors maintains <a
   3576     href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for
   3577     Tcl</a>.</li>
   3578   <li>libxml2 and libxslt are the default XML libraries for PHP5.</li>
   3579   <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is
   3580     an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and
   3581     libxslt as part of GNU ClasspathX project.</li>
   3582   <li>Patrick McPhee provides Rexx bindings fof libxml2 and libxslt, look for
   3583     <a href="http://www.interlog.com/~ptjm/software.html">RexxXML</a>.</li>
   3584   <li><a
   3585     href="http://www.satimage.fr/software/en/xml_suite.html">Satimage</a>
   3586     provides <a
   3587     href="http://www.satimage.fr/software/en/downloads_osaxen.html">XMLLib
   3588     osax</a>. This is an osax for Mac OS X with a set of commands to
   3589     implement in AppleScript the XML DOM, XPATH and XSLT. Also includes
   3590     commands for Property-lists (Apple's fast lookup table XML format.)</li>
   3591   <li>Francesco Montorsi developped <a
   3592     href="https://sourceforge.net/project/showfiles.php?group_id=51305&package_id=45182">wxXml2</a>
   3593     wrappers that interface libxml2, allowing wxWidgets applications to
   3594     load/save/edit XML instances.</li>
   3595 </ul>
   3596 
   3597 <p>The distribution includes a set of Python bindings, which are guaranteed
   3598 to be maintained as part of the library in the future, though the Python
   3599 interface have not yet reached the completeness of the C API.</p>
   3600 
   3601 <p>Note that some of the Python purist dislike the default set of Python
   3602 bindings, rather than complaining I suggest they have a look at <a
   3603 href="http://lxml.de/">lxml the more pythonic bindings for libxml2
   3604 and libxslt</a> and <a
   3605 href="http://lxml.de/mailinglist/">check the mailing-list</a>.</p>
   3606 
   3607 <p><a href="mailto:stephane.bidoul (a] softwareag.com">Stphane Bidoul</a>
   3608 maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port
   3609 of the Python bindings</a>.</p>
   3610 
   3611 <p>Note to people interested in building bindings, the API is formalized as
   3612 <a href="libxml2-api.xml">an XML API description file</a> which allows to
   3613 automate a large part of the Python bindings, this includes function
   3614 descriptions, enums, structures, typedefs, etc... The Python script used to
   3615 build the bindings is python/generator.py in the source distribution.</p>
   3616 
   3617 <p>To install the Python bindings there are 2 options:</p>
   3618 <ul>
   3619   <li>If you use an RPM based distribution, simply install the <a
   3620     href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python
   3621     RPM</a> (and if needed the <a
   3622     href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python
   3623     RPM</a>).</li>
   3624   <li>Otherwise use the <a href="ftp://xmlsoft.org/libxml2/python/">libxml2-python
   3625     module distribution</a> corresponding to your installed version of
   3626     libxml2 and libxslt. Note that to install it you will need both libxml2
   3627     and libxslt installed and run "python setup.py build install" in the
   3628     module tree.</li>
   3629 </ul>
   3630 
   3631 <p>The distribution includes a set of examples and regression tests for the
   3632 python bindings in the <code>python/tests</code> directory. Here are some
   3633 excerpts from those tests:</p>
   3634 
   3635 <h3>tst.py:</h3>
   3636 
   3637 <p>This is a basic test of the file interface and DOM navigation:</p>
   3638 <pre>import libxml2, sys
   3639 
   3640 doc = libxml2.parseFile("tst.xml")
   3641 if doc.name != "tst.xml":
   3642     print "doc.name failed"
   3643     sys.exit(1)
   3644 root = doc.children
   3645 if root.name != "doc":
   3646     print "root.name failed"
   3647     sys.exit(1)
   3648 child = root.children
   3649 if child.name != "foo":
   3650     print "child.name failed"
   3651     sys.exit(1)
   3652 doc.freeDoc()</pre>
   3653 
   3654 <p>The Python module is called libxml2; parseFile is the equivalent of
   3655 xmlParseFile (most of the bindings are automatically generated, and the xml
   3656 prefix is removed and the casing convention are kept). All node seen at the
   3657 binding level share the same subset of accessors:</p>
   3658 <ul>
   3659   <li><code>name</code> : returns the node name</li>
   3660   <li><code>type</code> : returns a string indicating the node type</li>
   3661   <li><code>content</code> : returns the content of the node, it is based on
   3662     xmlNodeGetContent() and hence is recursive.</li>
   3663   <li><code>parent</code> , <code>children</code>, <code>last</code>,
   3664     <code>next</code>, <code>prev</code>, <code>doc</code>,
   3665     <code>properties</code>: pointing to the associated element in the tree,
   3666     those may return None in case no such link exists.</li>
   3667 </ul>
   3668 
   3669 <p>Also note the need to explicitly deallocate documents with freeDoc() .
   3670 Reference counting for libxml2 trees would need quite a lot of work to
   3671 function properly, and rather than risk memory leaks if not implemented
   3672 correctly it sounds safer to have an explicit function to free a tree. The
   3673 wrapper python objects like doc, root or child are them automatically garbage
   3674 collected.</p>
   3675 
   3676 <h3>validate.py:</h3>
   3677 
   3678 <p>This test check the validation interfaces and redirection of error
   3679 messages:</p>
   3680 <pre>import libxml2
   3681 
   3682 #deactivate error messages from the validation
   3683 def noerr(ctx, str):
   3684     pass
   3685 
   3686 libxml2.registerErrorHandler(noerr, None)
   3687 
   3688 ctxt = libxml2.createFileParserCtxt("invalid.xml")
   3689 ctxt.validate(1)
   3690 ctxt.parseDocument()
   3691 doc = ctxt.doc()
   3692 valid = ctxt.isValid()
   3693 doc.freeDoc()
   3694 if valid != 0:
   3695     print "validity check failed"</pre>
   3696 
   3697 <p>The first thing to notice is the call to registerErrorHandler(), it
   3698 defines a new error handler global to the library. It is used to avoid seeing
   3699 the error messages when trying to validate the invalid document.</p>
   3700 
   3701 <p>The main interest of that test is the creation of a parser context with
   3702 createFileParserCtxt() and how the behaviour can be changed before calling
   3703 parseDocument() . Similarly the information resulting from the parsing phase
   3704 is also available using context methods.</p>
   3705 
   3706 <p>Contexts like nodes are defined as class and the libxml2 wrappers maps the
   3707 C function interfaces in terms of objects method as much as possible. The
   3708 best to get a complete view of what methods are supported is to look at the
   3709 libxml2.py module containing all the wrappers.</p>
   3710 
   3711 <h3>push.py:</h3>
   3712 
   3713 <p>This test show how to activate the push parser interface:</p>
   3714 <pre>import libxml2
   3715 
   3716 ctxt = libxml2.createPushParser(None, "&lt;foo", 4, "test.xml")
   3717 ctxt.parseChunk("/&gt;", 2, 1)
   3718 doc = ctxt.doc()
   3719 
   3720 doc.freeDoc()</pre>
   3721 
   3722 <p>The context is created with a special call based on the
   3723 xmlCreatePushParser() from the C library. The first argument is an optional
   3724 SAX callback object, then the initial set of data, the length and the name of
   3725 the resource in case URI-References need to be computed by the parser.</p>
   3726 
   3727 <p>Then the data are pushed using the parseChunk() method, the last call
   3728 setting the third argument terminate to 1.</p>
   3729 
   3730 <h3>pushSAX.py:</h3>
   3731 
   3732 <p>this test show the use of the event based parsing interfaces. In this case
   3733 the parser does not build a document, but provides callback information as
   3734 the parser makes progresses analyzing the data being provided:</p>
   3735 <pre>import libxml2
   3736 log = ""
   3737 
   3738 class callback:
   3739     def startDocument(self):
   3740         global log
   3741         log = log + "startDocument:"
   3742 
   3743     def endDocument(self):
   3744         global log
   3745         log = log + "endDocument:"
   3746 
   3747     def startElement(self, tag, attrs):
   3748         global log
   3749         log = log + "startElement %s %s:" % (tag, attrs)
   3750 
   3751     def endElement(self, tag):
   3752         global log
   3753         log = log + "endElement %s:" % (tag)
   3754 
   3755     def characters(self, data):
   3756         global log
   3757         log = log + "characters: %s:" % (data)
   3758 
   3759     def warning(self, msg):
   3760         global log
   3761         log = log + "warning: %s:" % (msg)
   3762 
   3763     def error(self, msg):
   3764         global log
   3765         log = log + "error: %s:" % (msg)
   3766 
   3767     def fatalError(self, msg):
   3768         global log
   3769         log = log + "fatalError: %s:" % (msg)
   3770 
   3771 handler = callback()
   3772 
   3773 ctxt = libxml2.createPushParser(handler, "&lt;foo", 4, "test.xml")
   3774 chunk = " url='tst'&gt;b"
   3775 ctxt.parseChunk(chunk, len(chunk), 0)
   3776 chunk = "ar&lt;/foo&gt;"
   3777 ctxt.parseChunk(chunk, len(chunk), 1)
   3778 
   3779 reference = "startDocument:startElement foo {'url': 'tst'}:" + \ 
   3780             "characters: bar:endElement foo:endDocument:"
   3781 if log != reference:
   3782     print "Error got: %s" % log
   3783     print "Expected: %s" % reference</pre>
   3784 
   3785 <p>The key object in that test is the handler, it provides a number of entry
   3786 points which can be called by the parser as it makes progresses to indicate
   3787 the information set obtained. The full set of callback is larger than what
   3788 the callback class in that specific example implements (see the SAX
   3789 definition for a complete list). The wrapper will only call those supplied by
   3790 the object when activated. The startElement receives the names of the element
   3791 and a dictionary containing the attributes carried by this element.</p>
   3792 
   3793 <p>Also note that the reference string generated from the callback shows a
   3794 single character call even though the string "bar" is passed to the parser
   3795 from 2 different call to parseChunk()</p>
   3796 
   3797 <h3>xpath.py:</h3>
   3798 
   3799 <p>This is a basic test of XPath wrappers support</p>
   3800 <pre>import libxml2
   3801 
   3802 doc = libxml2.parseFile("tst.xml")
   3803 ctxt = doc.xpathNewContext()
   3804 res = ctxt.xpathEval("//*")
   3805 if len(res) != 2:
   3806     print "xpath query: wrong node set size"
   3807     sys.exit(1)
   3808 if res[0].name != "doc" or res[1].name != "foo":
   3809     print "xpath query: wrong node set value"
   3810     sys.exit(1)
   3811 doc.freeDoc()
   3812 ctxt.xpathFreeContext()</pre>
   3813 
   3814 <p>This test parses a file, then create an XPath context to evaluate XPath
   3815 expression on it. The xpathEval() method execute an XPath query and returns
   3816 the result mapped in a Python way. String and numbers are natively converted,
   3817 and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like
   3818 the document, the XPath context need to be freed explicitly, also not that
   3819 the result of the XPath query may point back to the document tree and hence
   3820 the document must be freed after the result of the query is used.</p>
   3821 
   3822 <h3>xpathext.py:</h3>
   3823 
   3824 <p>This test shows how to extend the XPath engine with functions written in
   3825 python:</p>
   3826 <pre>import libxml2
   3827 
   3828 def foo(ctx, x):
   3829     return x + 1
   3830 
   3831 doc = libxml2.parseFile("tst.xml")
   3832 ctxt = doc.xpathNewContext()
   3833 libxml2.registerXPathFunction(ctxt._o, "foo", None, foo)
   3834 res = ctxt.xpathEval("foo(1)")
   3835 if res != 2:
   3836     print "xpath extension failure"
   3837 doc.freeDoc()
   3838 ctxt.xpathFreeContext()</pre>
   3839 
   3840 <p>Note how the extension function is registered with the context (but that
   3841 part is not yet finalized, this may change slightly in the future).</p>
   3842 
   3843 <h3>tstxpath.py:</h3>
   3844 
   3845 <p>This test is similar to the previous one but shows how the extension
   3846 function can access the XPath evaluation context:</p>
   3847 <pre>def foo(ctx, x):
   3848     global called
   3849 
   3850     #
   3851     # test that access to the XPath evaluation contexts
   3852     #
   3853     pctxt = libxml2.xpathParserContext(_obj=ctx)
   3854     ctxt = pctxt.context()
   3855     called = ctxt.function()
   3856     return x + 1</pre>
   3857 
   3858 <p>All the interfaces around the XPath parser(or rather evaluation) context
   3859 are not finalized, but it should be sufficient to do contextual work at the
   3860 evaluation point.</p>
   3861 
   3862 <h3>Memory debugging:</h3>
   3863 
   3864 <p>last but not least, all tests starts with the following prologue:</p>
   3865 <pre>#memory debug specific
   3866 libxml2.debugMemory(1)</pre>
   3867 
   3868 <p>and ends with the following epilogue:</p>
   3869 <pre>#memory debug specific
   3870 libxml2.cleanupParser()
   3871 if libxml2.debugMemory(1) == 0:
   3872     print "OK"
   3873 else:
   3874     print "Memory leak %d bytes" % (libxml2.debugMemory(1))
   3875     libxml2.dumpMemory()</pre>
   3876 
   3877 <p>Those activate the memory debugging interface of libxml2 where all
   3878 allocated block in the library are tracked. The prologue then cleans up the
   3879 library state and checks that all allocated memory has been freed. If not it
   3880 calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p>
   3881 
   3882 <h2><a name="architecture">libxml2 architecture</a></h2>
   3883 
   3884 <p>Libxml2 is made of multiple components; some of them are optional, and
   3885 most of the block interfaces are public. The main components are:</p>
   3886 <ul>
   3887   <li>an Input/Output layer</li>
   3888   <li>FTP and HTTP client layers (optional)</li>
   3889   <li>an Internationalization layer managing the encodings support</li>
   3890   <li>a URI module</li>
   3891   <li>the XML parser and its basic SAX interface</li>
   3892   <li>an HTML parser using the same SAX interface (optional)</li>
   3893   <li>a SAX tree module to build an in-memory DOM representation</li>
   3894   <li>a tree module to manipulate the DOM representation</li>
   3895   <li>a validation module using the DOM representation (optional)</li>
   3896   <li>an XPath module for global lookup in a DOM representation
   3897   (optional)</li>
   3898   <li>a debug module (optional)</li>
   3899 </ul>
   3900 
   3901 <p>Graphically this gives the following:</p>
   3902 
   3903 <p><img src="libxml.gif" alt="a graphical view of the various"></p>
   3904 
   3905 <p></p>
   3906 
   3907 <h2><a name="tree">The tree output</a></h2>
   3908 
   3909 <p>The parser returns a tree built during the document analysis. The value
   3910 returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an
   3911 <strong>xmlDoc</strong> structure). This structure contains information such
   3912 as the file name, the document type, and a <strong>children</strong> pointer
   3913 which is the root of the document (or more exactly the first child under the
   3914 root which is the document). The tree is made of <strong>xmlNode</strong>s,
   3915 chained in double-linked lists of siblings and with a children&lt;-&gt;parent
   3916 relationship. An xmlNode can also carry properties (a chain of xmlAttr
   3917 structures). An attribute may have a value which is a list of TEXT or
   3918 ENTITY_REF nodes.</p>
   3919 
   3920 <p>Here is an example (erroneous with respect to the XML spec since there
   3921 should be only one ELEMENT under the root):</p>
   3922 
   3923 <p><img src="structure.gif" alt=" structure.gif "></p>
   3924 
   3925 <p>In the source package there is a small program (not installed by default)
   3926 called <strong>xmllint</strong> which parses XML files given as argument and
   3927 prints them back as parsed. This is useful for detecting errors both in XML
   3928 code and in the XML parser itself. It has an option <strong>--debug</strong>
   3929 which prints the actual in-memory structure of the document; here is the
   3930 result with the <a href="#example">example</a> given before:</p>
   3931 <pre>DOCUMENT
   3932 version=1.0
   3933 standalone=true
   3934   ELEMENT EXAMPLE
   3935     ATTRIBUTE prop1
   3936       TEXT
   3937       content=gnome is great
   3938     ATTRIBUTE prop2
   3939       ENTITY_REF
   3940       TEXT
   3941       content= linux too 
   3942     ELEMENT head
   3943       ELEMENT title
   3944         TEXT
   3945         content=Welcome to Gnome
   3946     ELEMENT chapter
   3947       ELEMENT title
   3948         TEXT
   3949         content=The Linux adventure
   3950       ELEMENT p
   3951         TEXT
   3952         content=bla bla bla ...
   3953       ELEMENT image
   3954         ATTRIBUTE href
   3955           TEXT
   3956           content=linus.gif
   3957       ELEMENT p
   3958         TEXT
   3959         content=...</pre>
   3960 
   3961 <p>This should be useful for learning the internal representation model.</p>
   3962 
   3963 <h2><a name="interface">The SAX interface</a></h2>
   3964 
   3965 <p>Sometimes the DOM tree output is just too large to fit reasonably into
   3966 memory. In that case (and if you don't expect to save back the XML document
   3967 loaded using libxml), it's better to use the SAX interface of libxml. SAX is
   3968 a <strong>callback-based interface</strong> to the parser. Before parsing,
   3969 the application layer registers a customized set of callbacks which are
   3970 called by the library as it progresses through the XML input.</p>
   3971 
   3972 <p>To get more detailed step-by-step guidance on using the SAX interface of
   3973 libxml, see the <a
   3974 href="http://www.jamesh.id.au/articles/libxml-sax/libxml-sax.html">nice
   3975 documentation</a>.written by <a href="mailto:james (a] daa.com.au">James
   3976 Henstridge</a>.</p>
   3977 
   3978 <p>You can debug the SAX behaviour by using the <strong>testSAX</strong>
   3979 program located in the gnome-xml module (it's usually not shipped in the
   3980 binary packages of libxml, but you can find it in the tar source
   3981 distribution). Here is the sequence of callbacks that would be reported by
   3982 testSAX when parsing the example XML document shown earlier:</p>
   3983 <pre>SAX.setDocumentLocator()
   3984 SAX.startDocument()
   3985 SAX.getEntity(amp)
   3986 SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp;amp; linux too')
   3987 SAX.characters(   , 3)
   3988 SAX.startElement(head)
   3989 SAX.characters(    , 4)
   3990 SAX.startElement(title)
   3991 SAX.characters(Welcome to Gnome, 16)
   3992 SAX.endElement(title)
   3993 SAX.characters(   , 3)
   3994 SAX.endElement(head)
   3995 SAX.characters(   , 3)
   3996 SAX.startElement(chapter)
   3997 SAX.characters(    , 4)
   3998 SAX.startElement(title)
   3999 SAX.characters(The Linux adventure, 19)
   4000 SAX.endElement(title)
   4001 SAX.characters(    , 4)
   4002 SAX.startElement(p)
   4003 SAX.characters(bla bla bla ..., 15)
   4004 SAX.endElement(p)
   4005 SAX.characters(    , 4)
   4006 SAX.startElement(image, href='linus.gif')
   4007 SAX.endElement(image)
   4008 SAX.characters(    , 4)
   4009 SAX.startElement(p)
   4010 SAX.characters(..., 3)
   4011 SAX.endElement(p)
   4012 SAX.characters(   , 3)
   4013 SAX.endElement(chapter)
   4014 SAX.characters( , 1)
   4015 SAX.endElement(EXAMPLE)
   4016 SAX.endDocument()</pre>
   4017 
   4018 <p>Most of the other interfaces of libxml2 are based on the DOM tree-building
   4019 facility, so nearly everything up to the end of this document presupposes the
   4020 use of the standard DOM tree build. Note that the DOM tree itself is built by
   4021 a set of registered default callbacks, without internal specific
   4022 interface.</p>
   4023 
   4024 <h2><a name="Validation">Validation &amp; DTDs</a></h2>
   4025 
   4026 <p>Table of Content:</p>
   4027 <ol>
   4028   <li><a href="#General5">General overview</a></li>
   4029   <li><a href="#definition">The definition</a></li>
   4030   <li><a href="#Simple">Simple rules</a>
   4031     <ol>
   4032       <li><a href="#reference">How to reference a DTD from a document</a></li>
   4033       <li><a href="#Declaring">Declaring elements</a></li>
   4034       <li><a href="#Declaring1">Declaring attributes</a></li>
   4035     </ol>
   4036   </li>
   4037   <li><a href="#Some">Some examples</a></li>
   4038   <li><a href="#validate">How to validate</a></li>
   4039   <li><a href="#Other">Other resources</a></li>
   4040 </ol>
   4041 
   4042 <h3><a name="General5">General overview</a></h3>
   4043 
   4044 <p>Well what is validation and what is a DTD ?</p>
   4045 
   4046 <p>DTD is the acronym for Document Type Definition. This is a description of
   4047 the content for a family of XML files. This is part of the XML 1.0
   4048 specification, and allows one to describe and verify that a given document
   4049 instance conforms to the set of rules detailing its structure and content.</p>
   4050 
   4051 <p>Validation is the process of checking a document against a DTD (more
   4052 generally against a set of construction rules).</p>
   4053 
   4054 <p>The validation process and building DTDs are the two most difficult parts
   4055 of the XML life cycle. Briefly a DTD defines all the possible elements to be
   4056 found within your document, what is the formal shape of your document tree
   4057 (by defining the allowed content of an element; either text, a regular
   4058 expression for the allowed list of children, or mixed content i.e. both text
   4059 and children). The DTD also defines the valid attributes for all elements and
   4060 the types of those attributes.</p>
   4061 
   4062 <h3><a name="definition1">The definition</a></h3>
   4063 
   4064 <p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a
   4065 href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of
   4066 Rev1</a>):</p>
   4067 <ul>
   4068   <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring
   4069   elements</a></li>
   4070   <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring
   4071   attributes</a></li>
   4072 </ul>
   4073 
   4074 <p>(unfortunately) all this is inherited from the SGML world, the syntax is
   4075 ancient...</p>
   4076 
   4077 <h3><a name="Simple1">Simple rules</a></h3>
   4078 
   4079 <p>Writing DTDs can be done in many ways. The rules to build them if you need
   4080 something permanent or something which can evolve over time can be radically
   4081 different. Really complex DTDs like DocBook ones are flexible but quite
   4082 harder to design. I will just focus on DTDs for a formats with a fixed simple
   4083 structure. It is just a set of basic rules, and definitely not exhaustive nor
   4084 usable for complex DTD design.</p>
   4085 
   4086 <h4><a name="reference1">How to reference a DTD from a document</a>:</h4>
   4087 
   4088 <p>Assuming the top element of the document is <code>spec</code> and the dtd
   4089 is placed in the file <code>mydtd</code> in the subdirectory
   4090 <code>dtds</code> of the directory from where the document were loaded:</p>
   4091 
   4092 <p><code>&lt;!DOCTYPE spec SYSTEM "dtds/mydtd"&gt;</code></p>
   4093 
   4094 <p>Notes:</p>
   4095 <ul>
   4096   <li>The system string is actually an URI-Reference (as defined in <a
   4097     href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a
   4098     full URL string indicating the location of your DTD on the Web. This is a
   4099     really good thing to do if you want others to validate your document.</li>
   4100   <li>It is also possible to associate a <code>PUBLIC</code> identifier (a
   4101     magic string) so that the DTD is looked up in catalogs on the client side
   4102     without having to locate it on the web.</li>
   4103   <li>A DTD contains a set of element and attribute declarations, but they
   4104     don't define what the root of the document should be. This is explicitly
   4105     told to the parser/validator as the first element of the
   4106     <code>DOCTYPE</code> declaration.</li>
   4107 </ul>
   4108 
   4109 <h4><a name="Declaring2">Declaring elements</a>:</h4>
   4110 
   4111 <p>The following declares an element <code>spec</code>:</p>
   4112 
   4113 <p><code>&lt;!ELEMENT spec (front, body, back?)&gt;</code></p>
   4114 
   4115 <p>It also expresses that the spec element contains one <code>front</code>,
   4116 one <code>body</code> and one optional <code>back</code> children elements in
   4117 this order. The declaration of one element of the structure and its content
   4118 are done in a single declaration. Similarly the following declares
   4119 <code>div1</code> elements:</p>
   4120 
   4121 <p><code>&lt;!ELEMENT div1 (head, (p | list | note)*, div2?)&gt;</code></p>
   4122 
   4123 <p>which means div1 contains one <code>head</code> then a series of optional
   4124 <code>p</code>, <code>list</code>s and <code>note</code>s and then an
   4125 optional <code>div2</code>. And last but not least an element can contain
   4126 text:</p>
   4127 
   4128 <p><code>&lt;!ELEMENT b (#PCDATA)&gt;</code></p>
   4129 
   4130 <p><code>b</code> contains text or being of mixed content (text and elements
   4131 in no particular order):</p>
   4132 
   4133 <p><code>&lt;!ELEMENT p (#PCDATA|a|ul|b|i|em)*&gt;</code></p>
   4134 
   4135 <p><code>p </code>can contain text or <code>a</code>, <code>ul</code>,
   4136 <code>b</code>, <code>i </code>or <code>em</code> elements in no particular
   4137 order.</p>
   4138 
   4139 <h4><a name="Declaring1">Declaring attributes</a>:</h4>
   4140 
   4141 <p>Again the attributes declaration includes their content definition:</p>
   4142 
   4143 <p><code>&lt;!ATTLIST termdef name CDATA #IMPLIED&gt;</code></p>
   4144 
   4145 <p>means that the element <code>termdef</code> can have a <code>name</code>
   4146 attribute containing text (<code>CDATA</code>) and which is optional
   4147 (<code>#IMPLIED</code>). The attribute value can also be defined within a
   4148 set:</p>
   4149 
   4150 <p><code>&lt;!ATTLIST list type (bullets|ordered|glossary)
   4151 "ordered"&gt;</code></p>
   4152 
   4153 <p>means <code>list</code> element have a <code>type</code> attribute with 3
   4154 allowed values "bullets", "ordered" or "glossary" and which default to
   4155 "ordered" if the attribute is not explicitly specified.</p>
   4156 
   4157 <p>The content type of an attribute can be text (<code>CDATA</code>),
   4158 anchor/reference/references
   4159 (<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies)
   4160 (<code>ENTITY</code>/<code>ENTITIES</code>) or name(s)
   4161 (<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a
   4162 <code>chapter</code> element can have an optional <code>id</code> attribute
   4163 of type <code>ID</code>, usable for reference from attribute of type
   4164 IDREF:</p>
   4165 
   4166 <p><code>&lt;!ATTLIST chapter id ID #IMPLIED&gt;</code></p>
   4167 
   4168 <p>The last value of an attribute definition can be <code>#REQUIRED
   4169 </code>meaning that the attribute has to be given, <code>#IMPLIED</code>
   4170 meaning that it is optional, or the default value (possibly prefixed by
   4171 <code>#FIXED</code> if it is the only allowed).</p>
   4172 
   4173 <p>Notes:</p>
   4174 <ul>
   4175   <li>Usually the attributes pertaining to a given element are declared in a
   4176     single expression, but it is just a convention adopted by a lot of DTD
   4177     writers:
   4178     <pre>&lt;!ATTLIST termdef
   4179           id      ID      #REQUIRED
   4180           name    CDATA   #IMPLIED&gt;</pre>
   4181     <p>The previous construct defines both <code>id</code> and
   4182     <code>name</code> attributes for the element <code>termdef</code>.</p>
   4183   </li>
   4184 </ul>
   4185 
   4186 <h3><a name="Some1">Some examples</a></h3>
   4187 
   4188 <p>The directory <code>test/valid/dtds/</code> in the libxml2 distribution
   4189 contains some complex DTD examples. The example in the file
   4190 <code>test/valid/dia.xml</code> shows an XML file where the simple DTD is
   4191 directly included within the document.</p>
   4192 
   4193 <h3><a name="validate1">How to validate</a></h3>
   4194 
   4195 <p>The simplest way is to use the xmllint program included with libxml. The
   4196 <code>--valid</code> option turns-on validation of the files given as input.
   4197 For example the following validates a copy of the first revision of the XML
   4198 1.0 specification:</p>
   4199 
   4200 <p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p>
   4201 
   4202 <p>the -- noout is used to disable output of the resulting tree.</p>
   4203 
   4204 <p>The <code>--dtdvalid dtd</code> allows validation of the document(s)
   4205 against a given DTD.</p>
   4206 
   4207 <p>Libxml2 exports an API to handle DTDs and validation, check the <a
   4208 href="http://xmlsoft.org/html/libxml-valid.html">associated
   4209 description</a>.</p>
   4210 
   4211 <h3><a name="Other1">Other resources</a></h3>
   4212 
   4213 <p>DTDs are as old as SGML. So there may be a number of examples on-line, I
   4214 will just list one for now, others pointers welcome:</p>
   4215 <ul>
   4216   <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li>
   4217 </ul>
   4218 
   4219 <p>I suggest looking at the examples found under test/valid/dtd and any of
   4220 the large number of books available on XML. The dia example in test/valid
   4221 should be both simple and complete enough to allow you to build your own.</p>
   4222 
   4223 <p></p>
   4224 
   4225 <h2><a name="Memory">Memory Management</a></h2>
   4226 
   4227 <p>Table of Content:</p>
   4228 <ol>
   4229   <li><a href="#General3">General overview</a></li>
   4230   <li><a href="#setting">Setting libxml2 set of memory routines</a></li>
   4231   <li><a href="#cleanup">Cleaning up after using the library</a></li>
   4232   <li><a href="#Debugging">Debugging routines</a></li>
   4233   <li><a href="#General4">General memory requirements</a></li>
   4234   <li><a href="#Compacting">Returning memory to the kernel</a></li>
   4235 </ol>
   4236 
   4237 <h3><a name="General3">General overview</a></h3>
   4238 
   4239 <p>The module <code><a
   4240 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code>
   4241 provides the interfaces to the libxml2 memory system:</p>
   4242 <ul>
   4243   <li>libxml2 does not use the libc memory allocator directly but xmlFree(),
   4244     xmlMalloc() and xmlRealloc()</li>
   4245   <li>those routines can be reallocated to a specific set of routine, by
   4246     default the libc ones i.e. free(), malloc() and realloc()</li>
   4247   <li>the xmlmemory.c module includes a set of debugging routine</li>
   4248 </ul>
   4249 
   4250 <h3><a name="setting">Setting libxml2 set of memory routines</a></h3>
   4251 
   4252 <p>It is sometimes useful to not use the default memory allocator, either for
   4253 debugging, analysis or to implement a specific behaviour on memory management
   4254 (like on embedded systems). Two function calls are available to do so:</p>
   4255 <ul>
   4256   <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet
   4257     ()</a> which return the current set of functions in use by the parser</li>
   4258   <li><a
   4259     href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a>
   4260     which allow to set up a new set of memory allocation functions</li>
   4261 </ul>
   4262 
   4263 <p>Of course a call to xmlMemSetup() should probably be done before calling
   4264 any other libxml2 routines (unless you are sure your allocations routines are
   4265 compatibles).</p>
   4266 
   4267 <h3><a name="cleanup">Cleaning up after using the library</a></h3>
   4268 
   4269 <p>Libxml2 is not stateless, there is a few set of memory structures needing
   4270 allocation before the parser is fully functional (some encoding structures
   4271 for example). This also mean that once parsing is finished there is a tiny
   4272 amount of memory (a few hundred bytes) which can be recollected if you don't
   4273 reuse the library or any document built with it:</p>
   4274 <ul>
   4275   <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser
   4276     ()</a> is a centralized routine to free the library state and data. Note
   4277     that it won't deallocate any produced tree if any (use the xmlFreeDoc()
   4278     and related routines for this). This should be called only when the library
   4279     is not used anymore.</li>
   4280   <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser
   4281     ()</a> is the dual routine allowing to preallocate the parsing state
   4282     which can be useful for example to avoid initialization reentrancy
   4283     problems when using libxml2 in multithreaded applications</li>
   4284 </ul>
   4285 
   4286 <p>Generally xmlCleanupParser() is safe assuming no parsing is ongoing and
   4287 no document is still being used, if needed the state will be rebuild at the
   4288 next invocation of parser routines (or by xmlInitParser()), but be careful
   4289 of the consequences in multithreaded applications.</p>
   4290 
   4291 <h3><a name="Debugging">Debugging routines</a></h3>
   4292 
   4293 <p>When configured using --with-mem-debug flag (off by default), libxml2 uses
   4294 a set of memory allocation debugging routines keeping track of all allocated
   4295 blocks and the location in the code where the routine was called. A couple of
   4296 other debugging routines allow to dump the memory allocated infos to a file
   4297 or call a specific routine when a given block number is allocated:</p>
   4298 <ul>
   4299   <li><a
   4300     href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a>
   4301     <a
   4302     href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a>
   4303     and <a
   4304     href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a>
   4305     are the memory debugging replacement allocation routines</li>
   4306   <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump
   4307     ()</a> dumps all the information about the allocated memory block lefts
   4308     in the <code>.memdump</code> file</li>
   4309 </ul>
   4310 
   4311 <p>When developing libxml2 memory debug is enabled, the tests programs call
   4312 xmlMemoryDump () and the "make test" regression tests will check for any
   4313 memory leak during the full regression test sequence, this helps a lot
   4314 ensuring that libxml2  does not leak memory and bullet proof memory
   4315 allocations use (some libc implementations are known to be far too permissive
   4316 resulting in major portability problems!).</p>
   4317 
   4318 <p>If the .memdump reports a leak, it displays the allocation function and
   4319 also tries to give some information about the content and structure of the
   4320 allocated blocks left. This is sufficient in most cases to find the culprit,
   4321 but not always. Assuming the allocation problem is reproducible, it is
   4322 possible to find more easily:</p>
   4323 <ol>
   4324   <li>write down the block number xxxx not allocated</li>
   4325   <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest
   4326     when using GDB is to simply give the command
   4327     <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p>
   4328     <p>before running the program.</p>
   4329   </li>
   4330   <li>run the program under a debugger and set a breakpoint on
   4331     xmlMallocBreakpoint() a specific function called when this precise block
   4332     is allocated</li>
   4333   <li>when the breakpoint is reached you can then do a fine analysis of the
   4334     allocation an step  to see the condition resulting in the missing
   4335     deallocation.</li>
   4336 </ol>
   4337 
   4338 <p>I used to use a commercial tool to debug libxml2 memory problems but after
   4339 noticing that it was not detecting memory leaks that simple mechanism was
   4340 used and proved extremely efficient until now. Lately I have also used <a
   4341 href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some
   4342 success, it is tied to the i386 architecture since it works by emulating the
   4343 processor and instruction set, it is slow but  extremely efficient, i.e. it
   4344 spot memory usage errors in a very precise way.</p>
   4345 
   4346 <h3><a name="General4">General memory requirements</a></h3>
   4347 
   4348 <p>How much libxml2 memory require ? It's hard to tell in average it depends
   4349 of a number of things:</p>
   4350 <ul>
   4351   <li>the parser itself should work  in a fixed amount of memory, except for
   4352     information maintained about the stacks of names and  entities locations.
   4353     The I/O and encoding handlers will probably account for a few KBytes.
   4354     This is true for both the XML and HTML parser (though the HTML parser
   4355     need more state).</li>
   4356   <li>If you are generating the DOM tree then memory requirements will grow
   4357     nearly linear with the size of the data. In general for a balanced
   4358     textual document the internal memory requirement is about 4 times the
   4359     size of the UTF8 serialization of this document (example the XML-1.0
   4360     recommendation is a bit more of 150KBytes and takes 650KBytes of main
   4361     memory when parsed). Validation will add a amount of memory required for
   4362     maintaining the external Dtd state which should be linear with the
   4363     complexity of the content model defined by the Dtd</li>
   4364   <li>If you need to work with fixed memory requirements or don't need the
   4365     full DOM tree then using the <a href="xmlreader.html">xmlReader
   4366     interface</a> is probably the best way to proceed, it still allows to
   4367     validate or operate on subset of the tree if needed.</li>
   4368   <li>If you don't care about the advanced features of libxml2 like
   4369     validation, DOM, XPath or XPointer, don't use entities, need to work with
   4370     fixed memory requirements, and try to get the fastest parsing possible
   4371     then the SAX interface should be used, but it has known restrictions.</li>
   4372 </ul>
   4373 
   4374 <p></p>
   4375 <h3><a name="Compacting">Returning memory to the kernel</a></h3>
   4376 
   4377 <p>You may encounter that your process using libxml2 does not have a
   4378 reduced memory usage although you freed the trees. This is because
   4379 libxml2 allocates memory in a number of small chunks. When freeing one
   4380 of those chunks, the OS may decide that giving this little memory back
   4381 to the kernel will cause too much overhead and delay the operation. As
   4382 all chunks are this small, they get actually freed but not returned to
   4383 the kernel. On systems using glibc, there is a function call
   4384 "malloc_trim" from malloc.h which does this missing operation (note that
   4385 it is allowed to fail). Thus, after freeing your tree you may simply try
   4386 "malloc_trim(0);" to really get the memory back. If your OS does not
   4387 provide malloc_trim, try searching for a similar function.</p>
   4388 <p></p>
   4389 
   4390 <h2><a name="Encodings">Encodings support</a></h2>
   4391 
   4392 <p>If you are not really familiar with Internationalization (usual shortcut
   4393 is I18N) , Unicode, characters and glyphs, I suggest you read a <a
   4394 href="http://www.tbray.org/ongoing/When/200x/2003/04/06/Unicode">presentation</a>
   4395 by Tim Bray on Unicode and why you should care about it.</p>
   4396 
   4397 <p>If you don't understand why <b>it does not make sense to have a string
   4398 without knowing what encoding it uses</b>, then as Joel Spolsky said <a
   4399 href="http://www.joelonsoftware.com/articles/Unicode.html">please do not
   4400 write another line of code until you finish reading that article.</a>. It is
   4401 a prerequisite to understand this page, and avoid a lot of problems with
   4402 libxml2, XML or text processing in general.</p>
   4403 
   4404 <p>Table of Content:</p>
   4405 <ol>
   4406   <li><a href="encoding.html#What">What does internationalization support
   4407     mean ?</a></li>
   4408   <li><a href="encoding.html#internal">The internal encoding, how and
   4409   why</a></li>
   4410   <li><a href="encoding.html#implemente">How is it implemented ?</a></li>
   4411   <li><a href="encoding.html#Default">Default supported encodings</a></li>
   4412   <li><a href="encoding.html#extend">How to extend the existing
   4413   support</a></li>
   4414 </ol>
   4415 
   4416 <h3><a name="What">What does internationalization support mean ?</a></h3>
   4417 
   4418 <p>XML was designed from the start to allow the support of any character set
   4419 by using Unicode. Any conformant XML parser has to support the UTF-8 and
   4420 UTF-16 default encodings which can both express the full unicode ranges. UTF8
   4421 is a variable length encoding whose greatest points are to reuse the same
   4422 encoding for ASCII and to save space for Western encodings, but it is a bit
   4423 more complex to handle in practice. UTF-16 use 2 bytes per character (and
   4424 sometimes combines two pairs), it makes implementation easier, but looks a
   4425 bit overkill for Western languages encoding. Moreover the XML specification
   4426 allows the document to be encoded in other encodings at the condition that
   4427 they are clearly labeled as such. For example the following is a wellformed
   4428 XML document encoded in ISO-8859-1 and using accentuated letters that we
   4429 French like for both markup and content:</p>
   4430 <pre>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
   4431 &lt;tr&egrave;s&gt;l&agrave; &lt;/tr&egrave;s&gt;</pre>
   4432 
   4433 <p>Having internationalization support in libxml2 means the following:</p>
   4434 <ul>
   4435   <li>the document is properly parsed</li>
   4436   <li>information about it's encoding is saved</li>
   4437   <li>it can be modified</li>
   4438   <li>it can be saved in its original encoding</li>
   4439   <li>it can also be saved in another encoding supported by libxml2 (for
   4440     example straight UTF8 or even an ASCII form)</li>
   4441 </ul>
   4442 
   4443 <p>Another very important point is that the whole libxml2 API, with the
   4444 exception of a few routines to read with a specific encoding or save to a
   4445 specific encoding, is completely agnostic about the original encoding of the
   4446 document.</p>
   4447 
   4448 <p>It should be noted too that the HTML parser embedded in libxml2 now obey
   4449 the same rules too, the following document will be (as of 2.2.2) handled  in
   4450 an internationalized fashion by libxml2 too:</p>
   4451 <pre>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
   4452                       "http://www.w3.org/TR/REC-html40/loose.dtd"&gt;
   4453 &lt;html lang="fr"&gt;
   4454 &lt;head&gt;
   4455   &lt;META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&gt;
   4456 &lt;/head&gt;
   4457 &lt;body&gt;
   4458 &lt;p&gt;W3C cr&eacute;e des standards pour le Web.&lt;/body&gt;
   4459 &lt;/html&gt;</pre>
   4460 
   4461 <h3><a name="internal">The internal encoding, how and why</a></h3>
   4462 
   4463 <p>One of the core decisions was to force all documents to be converted to a
   4464 default internal encoding, and that encoding to be UTF-8, here are the
   4465 rationales for those choices:</p>
   4466 <ul>
   4467   <li>keeping the native encoding in the internal form would force the libxml
   4468     users (or the code associated) to be fully aware of the encoding of the
   4469     original document, for examples when adding a text node to a document,
   4470     the content would have to be provided in the document encoding, i.e. the
   4471     client code would have to check it before hand, make sure it's conformant
   4472     to the encoding, etc ... Very hard in practice, though in some specific
   4473     cases this may make sense.</li>
   4474   <li>the second decision was which encoding. From the XML spec only UTF8 and
   4475     UTF16 really makes sense as being the two only encodings for which there
   4476     is mandatory support. UCS-4 (32 bits fixed size encoding) could be
   4477     considered an intelligent choice too since it's a direct Unicode mapping
   4478     support. I selected UTF-8 on the basis of efficiency and compatibility
   4479     with surrounding software:
   4480     <ul>
   4481       <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly
   4482         more costly to import and export CPU wise) is also far more compact
   4483         than UTF-16 (and UCS-4) for a majority of the documents I see it used
   4484         for right now (RPM RDF catalogs, advogato data, various configuration
   4485         file formats, etc.) and the key point for today's computer
   4486         architecture is efficient uses of caches. If one nearly double the
   4487         memory requirement to store the same amount of data, this will trash
   4488         caches (main memory/external caches/internal caches) and my take is
   4489         that this harms the system far more than the CPU requirements needed
   4490         for the conversion to UTF-8</li>
   4491       <li>Most of libxml2 version 1 users were using it with straight ASCII
   4492         most of the time, doing the conversion with an internal encoding
   4493         requiring all their code to be rewritten was a serious show-stopper
   4494         for using UTF-16 or UCS-4.</li>
   4495       <li>UTF-8 is being used as the de-facto internal encoding standard for
   4496         related code like the <a href="http://www.pango.org/">pango</a>
   4497         upcoming Gnome text widget, and a lot of Unix code (yet another place
   4498         where Unix programmer base takes a different approach from Microsoft
   4499         - they are using UTF-16)</li>
   4500     </ul>
   4501   </li>
   4502 </ul>
   4503 
   4504 <p>What does this mean in practice for the libxml2 user:</p>
   4505 <ul>
   4506   <li>xmlChar, the libxml2 data type is a byte, those bytes must be assembled
   4507     as UTF-8 valid strings. The proper way to terminate an xmlChar * string
   4508     is simply to append 0 byte, as usual.</li>
   4509   <li>One just need to make sure that when using chars outside the ASCII set,
   4510     the values has been properly converted to UTF-8</li>
   4511 </ul>
   4512 
   4513 <h3><a name="implemente">How is it implemented ?</a></h3>
   4514 
   4515 <p>Let's describe how all this works within libxml, basically the I18N
   4516 (internationalization) support get triggered only during I/O operation, i.e.
   4517 when reading a document or saving one. Let's look first at the reading
   4518 sequence:</p>
   4519 <ol>
   4520   <li>when a document is processed, we usually don't know the encoding, a
   4521     simple heuristic allows to detect UTF-16 and UCS-4 from encodings where
   4522     the ASCII range (0-0x7F) maps with ASCII</li>
   4523   <li>the xml declaration if available is parsed, including the encoding
   4524     declaration. At that point, if the autodetected encoding is different
   4525     from the one declared a call to xmlSwitchEncoding() is issued.</li>
   4526   <li>If there is no encoding declaration, then the input has to be in either
   4527     UTF-8 or UTF-16, if it is not then at some point when processing the
   4528     input, the converter/checker of UTF-8 form will raise an encoding error.
   4529     You may end-up with a garbled document, or no document at all ! Example:
   4530     <pre>~/XML -&gt; ./xmllint err.xml 
   4531 err.xml:1: error: Input is not proper UTF-8, indicate encoding !
   4532 &lt;tr&egrave;s&gt;l&agrave;&lt;/tr&egrave;s&gt;
   4533    ^
   4534 err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C
   4535 &lt;tr&egrave;s&gt;l&agrave;&lt;/tr&egrave;s&gt;
   4536    ^</pre>
   4537   </li>
   4538   <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and
   4539     then search the default registered encoding converters for that encoding.
   4540     If it's not within the default set and iconv() support has been compiled
   4541     it, it will ask iconv for such an encoder. If this fails then the parser
   4542     will report an error and stops processing:
   4543     <pre>~/XML -&gt; ./xmllint err2.xml 
   4544 err2.xml:1: error: Unsupported encoding UnsupportedEnc
   4545 &lt;?xml version="1.0" encoding="UnsupportedEnc"?&gt;
   4546                                              ^</pre>
   4547   </li>
   4548   <li>From that point the encoder processes progressively the input (it is
   4549     plugged as a front-end to the I/O module) for that entity. It captures
   4550     and converts on-the-fly the document to be parsed to UTF-8. The parser
   4551     itself just does UTF-8 checking of this input and process it
   4552     transparently. The only difference is that the encoding information has
   4553     been added to the parsing context (more precisely to the input
   4554     corresponding to this entity).</li>
   4555   <li>The result (when using DOM) is an internal form completely in UTF-8
   4556     with just an encoding information on the document node.</li>
   4557 </ol>
   4558 
   4559 <p>Ok then what happens when saving the document (assuming you
   4560 collected/built an xmlDoc DOM like structure) ? It depends on the function
   4561 called, xmlSaveFile() will just try to save in the original encoding, while
   4562 xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given
   4563 encoding:</p>
   4564 <ol>
   4565   <li>if no encoding is given, libxml2 will look for an encoding value
   4566     associated to the document and if it exists will try to save to that
   4567     encoding,
   4568     <p>otherwise everything is written in the internal form, i.e. UTF-8</p>
   4569   </li>
   4570   <li>so if an encoding was specified, either at the API level or on the
   4571     document, libxml2 will again canonicalize the encoding name, lookup for a
   4572     converter in the registered set or through iconv. If not found the
   4573     function will return an error code</li>
   4574   <li>the converter is placed before the I/O buffer layer, as another kind of
   4575     buffer, then libxml2 will simply push the UTF-8 serialization to through
   4576     that buffer, which will then progressively be converted and pushed onto
   4577     the I/O layer.</li>
   4578   <li>It is possible that the converter code fails on some input, for example
   4579     trying to push an UTF-8 encoded Chinese character through the UTF-8 to
   4580     ISO-8859-1 converter won't work. Since the encoders are progressive they
   4581     will just report the error and the number of bytes converted, at that
   4582     point libxml2 will decode the offending character, remove it from the
   4583     buffer and replace it with the associated charRef encoding &amp;#123; and
   4584     resume the conversion. This guarantees that any document will be saved
   4585     without losses (except for markup names where this is not legal, this is
   4586     a problem in the current version, in practice avoid using non-ascii
   4587     characters for tag or attribute names). A special "ascii" encoding name
   4588     is used to save documents to a pure ascii form can be used when
   4589     portability is really crucial</li>
   4590 </ol>
   4591 
   4592 <p>Here are a few examples based on the same test document and assumin a
   4593 terminal using ISO-8859-1 as the text encoding:</p>
   4594 <pre>~/XML -&gt; ./xmllint isolat1 
   4595 &lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
   4596 &lt;tr&egrave;s&gt;l&lt;/tr&egrave;s&gt;
   4597 ~/XML -&gt; ./xmllint --encode UTF-8 isolat1 
   4598 &lt;?xml version="1.0" encoding="UTF-8"?&gt;
   4599 &lt;trs&gt;l &nbsp;&lt;/trs&gt;
   4600 ~/XML -&gt; </pre>
   4601 
   4602 <p>The same processing is applied (and reuse most of the code) for HTML I18N
   4603 processing. Looking up and modifying the content encoding is a bit more
   4604 difficult since it is located in a &lt;meta&gt; tag under the &lt;head&gt;,
   4605 so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have
   4606 been provided. The parser also attempts to switch encoding on the fly when
   4607 detecting such a tag on input. Except for that the processing is the same
   4608 (and again reuses the same code).</p>
   4609 
   4610 <h3><a name="Default">Default supported encodings</a></h3>
   4611 
   4612 <p>libxml2 has a set of default converters for the following encodings
   4613 (located in encoding.c):</p>
   4614 <ol>
   4615   <li>UTF-8 is supported by default (null handlers)</li>
   4616   <li>UTF-16, both little and big endian</li>
   4617   <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li>
   4618   <li>ASCII, useful mostly for saving</li>
   4619   <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML
   4620     predefined entities like &amp;copy; for the Copyright sign.</li>
   4621 </ol>
   4622 
   4623 <p>More over when compiled on an Unix platform with iconv support the full
   4624 set of encodings supported by iconv can be instantly be used by libxml. On a
   4625 linux machine with glibc-2.1 the list of supported encodings and aliases fill
   4626 3 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the
   4627 various Japanese ones.</p>
   4628 
   4629 <p>To convert from the UTF-8 values returned from the API to another encoding
   4630 then it is possible to use the function provided from <a
   4631 href="html/libxml-encoding.html">the encoding module</a> like <a
   4632 href="html/libxml-encoding.html#UTF8Toisolat1">UTF8Toisolat1</a>, or use the
   4633 POSIX <a
   4634 href="http://www.opengroup.org/onlinepubs/009695399/functions/iconv.html">iconv()</a>
   4635 API directly.</p>
   4636 
   4637 <h4>Encoding aliases</h4>
   4638 
   4639 <p>From 2.2.3, libxml2 has support to register encoding names aliases. The
   4640 goal is to be able to parse document whose encoding is supported but where
   4641 the name differs (for example from the default set of names accepted by
   4642 iconv). The following functions allow to register and handle new aliases for
   4643 existing encodings. Once registered libxml2 will automatically lookup the
   4644 aliases when handling a document:</p>
   4645 <ul>
   4646   <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li>
   4647   <li>int xmlDelEncodingAlias(const char *alias);</li>
   4648   <li>const char * xmlGetEncodingAlias(const char *alias);</li>
   4649   <li>void xmlCleanupEncodingAliases(void);</li>
   4650 </ul>
   4651 
   4652 <h3><a name="extend">How to extend the existing support</a></h3>
   4653 
   4654 <p>Well adding support for new encoding, or overriding one of the encoders
   4655 (assuming it is buggy) should not be hard, just write input and output
   4656 conversion routines to/from UTF-8, and register them using
   4657 xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx),  and they will be
   4658 called automatically if the parser(s) encounter such an encoding name
   4659 (register it uppercase, this will help). The description of the encoders,
   4660 their arguments and expected return values are described in the encoding.h
   4661 header.</p>
   4662 
   4663 <h2><a name="IO">I/O Interfaces</a></h2>
   4664 
   4665 <p>Table of Content:</p>
   4666 <ol>
   4667   <li><a href="#General1">General overview</a></li>
   4668   <li><a href="#basic">The basic buffer type</a></li>
   4669   <li><a href="#Input">Input I/O handlers</a></li>
   4670   <li><a href="#Output">Output I/O handlers</a></li>
   4671   <li><a href="#entities">The entities loader</a></li>
   4672   <li><a href="#Example2">Example of customized I/O</a></li>
   4673 </ol>
   4674 
   4675 <h3><a name="General1">General overview</a></h3>
   4676 
   4677 <p>The module <code><a
   4678 href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides
   4679 the interfaces to the libxml2 I/O system. This consists of 4 main parts:</p>
   4680 <ul>
   4681   <li>Entities loader, this is a routine which tries to fetch the entities
   4682     (files) based on their PUBLIC and SYSTEM identifiers. The default loader
   4683     don't look at the public identifier since libxml2 do not maintain a
   4684     catalog. You can redefine you own entity loader by using
   4685     <code>xmlGetExternalEntityLoader()</code> and
   4686     <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the
   4687     example</a>.</li>
   4688   <li>Input I/O buffers which are a commodity structure used by the parser(s)
   4689     input layer to handle fetching the information to feed the parser. This
   4690     provides buffering and is also a placeholder where the encoding
   4691     converters to UTF8 are piggy-backed.</li>
   4692   <li>Output I/O buffers are similar to the Input ones and fulfill similar
   4693     task but when generating a serialization from a tree.</li>
   4694   <li>A mechanism to register sets of I/O callbacks and associate them with
   4695     specific naming schemes like the protocol part of the URIs.
   4696     <p>This affect the default I/O operations and allows to use specific I/O
   4697     handlers for certain names.</p>
   4698   </li>
   4699 </ul>
   4700 
   4701 <p>The general mechanism used when loading http://rpmfind.net/xml.html for
   4702 example in the HTML parser is the following:</p>
   4703 <ol>
   4704   <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with
   4705     the parsing context and the URI string.</li>
   4706   <li>the URI string is checked against the existing registered handlers
   4707     using their match() callback function, if the HTTP module was compiled
   4708     in, it is registered and its match() function will succeeds</li>
   4709   <li>the open() function of the handler is called and if successful will
   4710     return an I/O Input buffer</li>
   4711   <li>the parser will the start reading from this buffer and progressively
   4712     fetch information from the resource, calling the read() function of the
   4713     handler until the resource is exhausted</li>
   4714   <li>if an encoding change is detected it will be installed on the input
   4715     buffer, providing buffering and efficient use of the conversion
   4716   routines</li>
   4717   <li>once the parser has finished, the close() function of the handler is
   4718     called once and the Input buffer and associated resources are
   4719   deallocated.</li>
   4720 </ol>
   4721 
   4722 <p>The user defined callbacks are checked first to allow overriding of the
   4723 default libxml2 I/O routines.</p>
   4724 
   4725 <h3><a name="basic">The basic buffer type</a></h3>
   4726 
   4727 <p>All the buffer manipulation handling is done using the
   4728 <code>xmlBuffer</code> type define in <code><a
   4729 href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a
   4730 resizable memory buffer. The buffer allocation strategy can be selected to be
   4731 either best-fit or use an exponential doubling one (CPU vs. memory use
   4732 trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and
   4733 <code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a
   4734 system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number
   4735 of functions allows to manipulate buffers with names starting with the
   4736 <code>xmlBuffer...</code> prefix.</p>
   4737 
   4738 <h3><a name="Input">Input I/O handlers</a></h3>
   4739 
   4740 <p>An Input I/O handler is a simple structure
   4741 <code>xmlParserInputBuffer</code> containing a context associated to the
   4742 resource (file descriptor, or pointer to a protocol handler), the read() and
   4743 close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset
   4744 encoding handler are also present to support charset conversion when
   4745 needed.</p>
   4746 
   4747 <h3><a name="Output">Output I/O handlers</a></h3>
   4748 
   4749 <p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an
   4750 Input one except the callbacks are write() and close().</p>
   4751 
   4752 <h3><a name="entities">The entities loader</a></h3>
   4753 
   4754 <p>The entity loader resolves requests for new entities and create inputs for
   4755 the parser. Creating an input from a filename or an URI string is done
   4756 through the xmlNewInputFromFile() routine.  The default entity loader do not
   4757 handle the PUBLIC identifier associated with an entity (if any). So it just
   4758 calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in
   4759 XML).</p>
   4760 
   4761 <p>If you want to hook up a catalog mechanism then you simply need to
   4762 override the default entity loader, here is an example:</p>
   4763 <pre>#include &lt;libxml/xmlIO.h&gt;
   4764 
   4765 xmlExternalEntityLoader defaultLoader = NULL;
   4766 
   4767 xmlParserInputPtr
   4768 xmlMyExternalEntityLoader(const char *URL, const char *ID,
   4769                                xmlParserCtxtPtr ctxt) {
   4770     xmlParserInputPtr ret;
   4771     const char *fileID = NULL;
   4772     /* lookup for the fileID depending on ID */
   4773 
   4774     ret = xmlNewInputFromFile(ctxt, fileID);
   4775     if (ret != NULL)
   4776         return(ret);
   4777     if (defaultLoader != NULL)
   4778         ret = defaultLoader(URL, ID, ctxt);
   4779     return(ret);
   4780 }
   4781 
   4782 int main(..) {
   4783     ...
   4784 
   4785     /*
   4786      * Install our own entity loader
   4787      */
   4788     defaultLoader = xmlGetExternalEntityLoader();
   4789     xmlSetExternalEntityLoader(xmlMyExternalEntityLoader);
   4790 
   4791     ...
   4792 }</pre>
   4793 
   4794 <h3><a name="Example2">Example of customized I/O</a></h3>
   4795 
   4796 <p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a
   4797 real use case</a>,  xmlDocDump() closes the FILE * passed by the application
   4798 and this was a problem. The <a
   4799 href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a
   4800 new output handler with the closing call deactivated:</p>
   4801 <ol>
   4802   <li>First define a new I/O output allocator where the output don't close
   4803     the file:
   4804     <pre>xmlOutputBufferPtr
   4805 xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) {
   4806 &nbsp;&nbsp;&nbsp;&nbsp;xmlOutputBufferPtr ret;
   4807 &nbsp;&nbsp;&nbsp;&nbsp;
   4808 &nbsp;&nbsp;&nbsp;&nbsp;if (xmlOutputCallbackInitialized == 0)
   4809 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;xmlRegisterDefaultOutputCallbacks();
   4810 
   4811 &nbsp;&nbsp;&nbsp;&nbsp;if (file == NULL) return(NULL);
   4812 &nbsp;&nbsp;&nbsp;&nbsp;ret = xmlAllocOutputBuffer(encoder);
   4813 &nbsp;&nbsp;&nbsp;&nbsp;if (ret != NULL) {
   4814 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ret-&gt;context = file;
   4815 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ret-&gt;writecallback = xmlFileWrite;
   4816 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ret-&gt;closecallback = NULL;  /* No close callback */
   4817 &nbsp;&nbsp;&nbsp;&nbsp;}
   4818 &nbsp;&nbsp;&nbsp;&nbsp;return(ret);
   4819 } </pre>
   4820   </li>
   4821   <li>And then use it to save the document:
   4822     <pre>FILE *f;
   4823 xmlOutputBufferPtr output;
   4824 xmlDocPtr doc;
   4825 int res;
   4826 
   4827 f = ...
   4828 doc = ....
   4829 
   4830 output = xmlOutputBufferCreateOwn(f, NULL);
   4831 res = xmlSaveFileTo(output, doc, NULL);
   4832     </pre>
   4833   </li>
   4834 </ol>
   4835 
   4836 <h2><a name="Catalog">Catalog support</a></h2>
   4837 
   4838 <p>Table of Content:</p>
   4839 <ol>
   4840   <li><a href="General2">General overview</a></li>
   4841   <li><a href="#definition">The definition</a></li>
   4842   <li><a href="#Simple">Using catalogs</a></li>
   4843   <li><a href="#Some">Some examples</a></li>
   4844   <li><a href="#reference">How to tune  catalog usage</a></li>
   4845   <li><a href="#validate">How to debug catalog processing</a></li>
   4846   <li><a href="#Declaring">How to create and maintain catalogs</a></li>
   4847   <li><a href="#implemento">The implementor corner quick review of the
   4848   API</a></li>
   4849   <li><a href="#Other">Other resources</a></li>
   4850 </ol>
   4851 
   4852 <h3><a name="General2">General overview</a></h3>
   4853 
   4854 <p>What is a catalog? Basically it's a lookup mechanism used when an entity
   4855 (a file or a remote resource) references another entity. The catalog lookup
   4856 is inserted between the moment the reference is recognized by the software
   4857 (XML parser, stylesheet processing, or even images referenced for inclusion
   4858 in a rendering) and the time where loading that resource is actually
   4859 started.</p>
   4860 
   4861 <p>It is basically used for 3 things:</p>
   4862 <ul>
   4863   <li>mapping from "logical" names, the public identifiers and a more
   4864     concrete name usable for download (and URI). For example it can associate
   4865     the logical name
   4866     <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p>
   4867     <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be
   4868     downloaded</p>
   4869     <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p>
   4870   </li>
   4871   <li>remapping from a given URL to another one, like an HTTP indirection
   4872     saying that
   4873     <p>"http://www.oasis-open.org/committes/tr.xsl"</p>
   4874     <p>should really be looked at</p>
   4875     <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p>
   4876   </li>
   4877   <li>providing a local cache mechanism allowing to load the entities
   4878     associated to public identifiers or remote resources, this is a really
   4879     important feature for any significant deployment of XML or SGML since it
   4880     allows to avoid the aleas and delays associated to fetching remote
   4881     resources.</li>
   4882 </ul>
   4883 
   4884 <h3><a name="definition">The definitions</a></h3>
   4885 
   4886 <p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p>
   4887 <ul>
   4888   <li>the older SGML catalogs, the official spec is  SGML Open Technical
   4889     Resolution TR9401:1997, but is better understood by reading <a
   4890     href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from
   4891     James Clark. This is relatively old and not the preferred mode of
   4892     operation of libxml.</li>
   4893   <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML
   4894     Catalogs</a> is far more flexible, more recent, uses an XML syntax and
   4895     should scale quite better. This is the default option of libxml.</li>
   4896 </ul>
   4897 
   4898 <p></p>
   4899 
   4900 <h3><a name="Simple">Using catalog</a></h3>
   4901 
   4902 <p>In a normal environment libxml2 will by default check the presence of a
   4903 catalog in /etc/xml/catalog, and assuming it has been correctly populated,
   4904 the processing is completely transparent to the document user. To take a
   4905 concrete example, suppose you are authoring a DocBook document, this one
   4906 starts with the following DOCTYPE definition:</p>
   4907 <pre>&lt;?xml version='1.0'?&gt;
   4908 &lt;!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN"
   4909           "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"&gt;</pre>
   4910 
   4911 <p>When validating the document with libxml, the catalog will be
   4912 automatically consulted to lookup the public identifier "-//Norman Walsh//DTD
   4913 DocBk XML V3.1.4//EN" and the system identifier
   4914 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have
   4915 been installed on your system and the catalogs actually point to them, libxml
   4916 will fetch them from the local disk.</p>
   4917 
   4918 <p style="font-size: 10pt"><strong>Note</strong>: Really don't use this
   4919 DOCTYPE example it's a really old version, but is fine as an example.</p>
   4920 
   4921 <p>Libxml2 will check the catalog each time that it is requested to load an
   4922 entity, this includes DTD, external parsed entities, stylesheets, etc ... If
   4923 your system is correctly configured all the authoring phase and processing
   4924 should use only local files, even if your document stays portable because it
   4925 uses the canonical public and system ID, referencing the remote document.</p>
   4926 
   4927 <h3><a name="Some">Some examples:</a></h3>
   4928 
   4929 <p>Here is a couple of fragments from XML Catalogs used in libxml2 early
   4930 regression tests in <code>test/catalogs</code> :</p>
   4931 <pre>&lt;?xml version="1.0"?&gt;
   4932 &lt;!DOCTYPE catalog PUBLIC 
   4933    "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
   4934    "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
   4935 &lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
   4936   &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
   4937    uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
   4938 ...</pre>
   4939 
   4940 <p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are
   4941 written in XML,  there is a specific namespace for catalog elements
   4942 "urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this
   4943 catalog is a <code>public</code> mapping it allows to associate a Public
   4944 Identifier with an URI.</p>
   4945 <pre>...
   4946     &lt;rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/"
   4947                    rewritePrefix="file:///usr/share/xml/docbook/"/&gt;
   4948 ...</pre>
   4949 
   4950 <p>A <code>rewriteSystem</code> is a very powerful instruction, it says that
   4951 any URI starting with a given prefix should be looked at another  URI
   4952 constructed by replacing the prefix with an new one. In effect this acts like
   4953 a cache system for a full area of the Web. In practice it is extremely useful
   4954 with a file prefix if you have installed a copy of those resources on your
   4955 local system.</p>
   4956 <pre>...
   4957 &lt;delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //"
   4958                 catalog="file:///usr/share/xml/docbook.xml"/&gt;
   4959 &lt;delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML"
   4960                 catalog="file:///usr/share/xml/docbook.xml"/&gt;
   4961 &lt;delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML"
   4962                 catalog="file:///usr/share/xml/docbook.xml"/&gt;
   4963 &lt;delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/"
   4964                 catalog="file:///usr/share/xml/docbook.xml"/&gt;
   4965 &lt;delegateURI uriStartString="http://www.oasis-open.org/docbook/"
   4966                 catalog="file:///usr/share/xml/docbook.xml"/&gt;
   4967 ...</pre>
   4968 
   4969 <p>Delegation is the core features which allows to build a tree of catalogs,
   4970 easier to maintain than a single catalog, based on Public Identifier, System
   4971 Identifier or URI prefixes it instructs the catalog software to look up
   4972 entries in another resource. This feature allow to build hierarchies of
   4973 catalogs, the set of entries presented should be sufficient to redirect the
   4974 resolution of all DocBook references to the specific catalog in
   4975 <code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all
   4976 references for DocBook 4.2.1 to a specific catalog installed at the same time
   4977 as the DocBook resources on the local machine.</p>
   4978 
   4979 <h3><a name="reference">How to tune catalog usage:</a></h3>
   4980 
   4981 <p>The user can change the default catalog behaviour by redirecting queries
   4982 to its own set of catalogs, this can be done by setting the
   4983 <code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an
   4984 empty one should deactivate loading the default <code>/etc/xml/catalog</code>
   4985 default catalog</p>
   4986 
   4987 <h3><a name="validate">How to debug catalog processing:</a></h3>
   4988 
   4989 <p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will
   4990 make libxml2 output debugging information for each catalog operations, for
   4991 example:</p>
   4992 <pre>orchis:~/XML -&gt; xmllint --memory --noout test/ent2
   4993 warning: failed to load external entity "title.xml"
   4994 orchis:~/XML -&gt; export XML_DEBUG_CATALOG=
   4995 orchis:~/XML -&gt; xmllint --memory --noout test/ent2
   4996 Failed to parse catalog /etc/xml/catalog
   4997 Failed to parse catalog /etc/xml/catalog
   4998 warning: failed to load external entity "title.xml"
   4999 Catalogs cleanup
   5000 orchis:~/XML -&gt; </pre>
   5001 
   5002 <p>The test/ent2 references an entity, running the parser from memory makes
   5003 the base URI unavailable and the the "title.xml" entity cannot be loaded.
   5004 Setting up the debug environment variable allows to detect that an attempt is
   5005 made to load the <code>/etc/xml/catalog</code> but since it's not present the
   5006 resolution fails.</p>
   5007 
   5008 <p>But the most advanced way to debug XML catalog processing is to use the
   5009 <strong>xmlcatalog</strong> command shipped with libxml2, it allows to load
   5010 catalogs and make resolution queries to see what is going on. This is also
   5011 used for the regression tests:</p>
   5012 <pre>orchis:~/XML -&gt; ./xmlcatalog test/catalogs/docbook.xml \
   5013                    "-//OASIS//DTD DocBook XML V4.1.2//EN"
   5014 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
   5015 orchis:~/XML -&gt; </pre>
   5016 
   5017 <p>For debugging what is going on, adding one -v flags increase the verbosity
   5018 level to indicate the processing done (adding a second flag also indicate
   5019 what elements are recognized at parsing):</p>
   5020 <pre>orchis:~/XML -&gt; ./xmlcatalog -v test/catalogs/docbook.xml \
   5021                    "-//OASIS//DTD DocBook XML V4.1.2//EN"
   5022 Parsing catalog test/catalogs/docbook.xml's content
   5023 Found public match -//OASIS//DTD DocBook XML V4.1.2//EN
   5024 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
   5025 Catalogs cleanup
   5026 orchis:~/XML -&gt; </pre>
   5027 
   5028 <p>A shell interface is also available to debug and process multiple queries
   5029 (and for regression tests):</p>
   5030 <pre>orchis:~/XML -&gt; ./xmlcatalog -shell test/catalogs/docbook.xml \
   5031                    "-//OASIS//DTD DocBook XML V4.1.2//EN"
   5032 &gt; help   
   5033 Commands available:
   5034 public PublicID: make a PUBLIC identifier lookup
   5035 system SystemID: make a SYSTEM identifier lookup
   5036 resolve PublicID SystemID: do a full resolver lookup
   5037 add 'type' 'orig' 'replace' : add an entry
   5038 del 'values' : remove values
   5039 dump: print the current catalog state
   5040 debug: increase the verbosity level
   5041 quiet: decrease the verbosity level
   5042 exit:  quit the shell
   5043 &gt; public "-//OASIS//DTD DocBook XML V4.1.2//EN"
   5044 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
   5045 &gt; quit
   5046 orchis:~/XML -&gt; </pre>
   5047 
   5048 <p>This should be sufficient for most debugging purpose, this was actually
   5049 used heavily to debug the XML Catalog implementation itself.</p>
   5050 
   5051 <h3><a name="Declaring">How to create and maintain</a> catalogs:</h3>
   5052 
   5053 <p>Basically XML Catalogs are XML files, you can either use XML tools to
   5054 manage them or use  <strong>xmlcatalog</strong> for this. The basic step is
   5055 to create a catalog the -create option provide this facility:</p>
   5056 <pre>orchis:~/XML -&gt; ./xmlcatalog --create tst.xml
   5057 &lt;?xml version="1.0"?&gt;
   5058 &lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
   5059          "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
   5060 &lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
   5061 orchis:~/XML -&gt; </pre>
   5062 
   5063 <p>By default xmlcatalog does not overwrite the original catalog and save the
   5064 result on the standard output, this can be overridden using the -noout
   5065 option. The <code>-add</code> command allows to add entries in the
   5066 catalog:</p>
   5067 <pre>orchis:~/XML -&gt; ./xmlcatalog --noout --create --add "public" \
   5068   "-//OASIS//DTD DocBook XML V4.1.2//EN" \
   5069   http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml
   5070 orchis:~/XML -&gt; cat tst.xml
   5071 &lt;?xml version="1.0"?&gt;
   5072 &lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \
   5073   "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
   5074 &lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"&gt;
   5075 &lt;public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
   5076         uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/&gt;
   5077 &lt;/catalog&gt;
   5078 orchis:~/XML -&gt; </pre>
   5079 
   5080 <p>The <code>-add</code> option will always take 3 parameters even if some of
   5081 the XML Catalog constructs (like nextCatalog) will have only a single
   5082 argument, just pass a third empty string, it will be ignored.</p>
   5083 
   5084 <p>Similarly the <code>-del</code> option remove matching entries from the
   5085 catalog:</p>
   5086 <pre>orchis:~/XML -&gt; ./xmlcatalog --del \
   5087   "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml
   5088 &lt;?xml version="1.0"?&gt;
   5089 &lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN"
   5090     "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"&gt;
   5091 &lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/&gt;
   5092 orchis:~/XML -&gt; </pre>
   5093 
   5094 <p>The catalog is now empty. Note that the matching of <code>-del</code> is
   5095 exact and would have worked in a similar fashion with the Public ID
   5096 string.</p>
   5097 
   5098 <p>This is rudimentary but should be sufficient to manage a not too complex
   5099 catalog tree of resources.</p>
   5100 
   5101 <h3><a name="implemento">The implementor corner quick review of the
   5102 API:</a></h3>
   5103 
   5104 <p>First, and like for every other module of libxml, there is an
   5105 automatically generated <a href="html/libxml-catalog.html">API page for
   5106 catalog support</a>.</p>
   5107 
   5108 <p>The header for the catalog interfaces should be included as:</p>
   5109 <pre>#include &lt;libxml/catalog.h&gt;</pre>
   5110 
   5111 <p>The API is voluntarily kept very simple. First it is not obvious that
   5112 applications really need access to it since it is the default behaviour of
   5113 libxml2 (Note: it is possible to completely override libxml2 default catalog
   5114 by using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to
   5115 plug an application specific resolver).</p>
   5116 
   5117 <p>Basically libxml2 support 2 catalog lists:</p>
   5118 <ul>
   5119   <li>the default one, global shared by all the application</li>
   5120   <li>a per-document catalog, this one is built if the document uses the
   5121     <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is
   5122     associated to the parser context and destroyed when the parsing context
   5123     is destroyed.</li>
   5124 </ul>
   5125 
   5126 <p>the document one will be used first if it exists.</p>
   5127 
   5128 <h4>Initialization routines:</h4>
   5129 
   5130 <p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be
   5131 used at startup to initialize the catalog, if the catalog should be
   5132 initialized with specific values xmlLoadCatalog()  or xmlLoadCatalogs()
   5133 should be called before xmlInitializeCatalog() which would otherwise do a
   5134 default initialization first.</p>
   5135 
   5136 <p>The xmlCatalogAddLocal() call is used by the parser to grow the document
   5137 own catalog list if needed.</p>
   5138 
   5139 <h4>Preferences setup:</h4>
   5140 
   5141 <p>The XML Catalog spec requires the possibility to select default
   5142 preferences between  public and system delegation,
   5143 xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and
   5144 xmlCatalogGetDefaults() allow to control  if XML Catalogs resolution should
   5145 be forbidden, allowed for global catalog, for document catalog or both, the
   5146 default is to allow both.</p>
   5147 
   5148 <p>And of course xmlCatalogSetDebug() allows to generate debug messages
   5149 (through the xmlGenericError() mechanism).</p>
   5150 
   5151 <h4>Querying routines:</h4>
   5152 
   5153 <p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic()
   5154 and xmlCatalogResolveURI() are relatively explicit if you read the XML
   5155 Catalog specification they correspond to section 7 algorithms, they should
   5156 also work if you have loaded an SGML catalog with a simplified semantic.</p>
   5157 
   5158 <p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but
   5159 operate on the document catalog list</p>
   5160 
   5161 <h4>Cleanup and Miscellaneous:</h4>
   5162 
   5163 <p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is
   5164 the per-document equivalent.</p>
   5165 
   5166 <p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the
   5167 first catalog in the global list, and xmlCatalogDump() allows to dump a
   5168 catalog state, those routines are primarily designed for xmlcatalog, I'm not
   5169 sure that exposing more complex interfaces (like navigation ones) would be
   5170 really useful.</p>
   5171 
   5172 <p>The xmlParseCatalogFile() is a function used to load XML Catalog files,
   5173 it's similar as xmlParseFile() except it bypass all catalog lookups, it's
   5174 provided because this functionality may be useful for client tools.</p>
   5175 
   5176 <h4>threaded environments:</h4>
   5177 
   5178 <p>Since the catalog tree is built progressively, some care has been taken to
   5179 try to avoid troubles in multithreaded environments. The code is now thread
   5180 safe assuming that the libxml2 library has been compiled with threads
   5181 support.</p>
   5182 
   5183 <p></p>
   5184 
   5185 <h3><a name="Other">Other resources</a></h3>
   5186 
   5187 <p>The XML Catalog specification is relatively recent so there isn't much
   5188 literature to point at:</p>
   5189 <ul>
   5190   <li>You can find a good rant from Norm Walsh about <a
   5191     href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the
   5192     need for catalogs</a>, it provides a lot of context information even if
   5193     I don't agree with everything presented. Norm also wrote a more recent
   5194     article <a
   5195     href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML
   5196     entities and URI resolvers</a> describing them.</li>
   5197   <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML
   5198     catalog proposal</a> from John Cowan</li>
   5199   <li>The <a href="http://www.rddl.org/">Resource Directory Description
   5200     Language</a> (RDDL) another catalog system but more oriented toward
   5201     providing metadata for XML namespaces.</li>
   5202   <li>the page from the OASIS Technical <a
   5203     href="http://www.oasis-open.org/committees/entity/">Committee on Entity
   5204     Resolution</a> who maintains XML Catalog, you will find pointers to the
   5205     specification update, some background and pointers to others tools
   5206     providing XML Catalog support</li>
   5207   <li>There is a <a href="buildDocBookCatalog">shell script</a> to generate
   5208     XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/
   5209     directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on
   5210     the resources found on the system. Otherwise it will just create
   5211     ~/xmlcatalog and ~/dbkxmlcatalog and doing:
   5212     <p><code>export XML_CATALOG_FILES=$HOME/xmlcatalog</code></p>
   5213     <p>should allow to process DocBook documentations without requiring
   5214     network accesses for the DTD or stylesheets</p>
   5215   </li>
   5216   <li>I have uploaded <a href="ftp://xmlsoft.org/libxml2/test/dbk412catalog.tar.gz">a
   5217     small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems
   5218     to work fine for me too</li>
   5219   <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog
   5220     manual page</a></li>
   5221 </ul>
   5222 
   5223 <p>If you have suggestions for corrections or additions, simply contact
   5224 me:</p>
   5225 
   5226 <h2><a name="library">The parser interfaces</a></h2>
   5227 
   5228 <p>This section is directly intended to help programmers getting bootstrapped
   5229 using the XML tollkit from the C language. It is not intended to be
   5230 extensive. I hope the automatically generated documents will provide the
   5231 completeness required, but as a separate set of documents. The interfaces of
   5232 the XML parser are by principle low level, Those interested in a higher level
   5233 API should <a href="#DOM">look at DOM</a>.</p>
   5234 
   5235 <p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are
   5236 separated from the <a href="html/libxml-htmlparser.html">HTML parser
   5237 interfaces</a>.  Let's have a look at how the XML parser can be called:</p>
   5238 
   5239 <h3><a name="Invoking">Invoking the parser : the pull method</a></h3>
   5240 
   5241 <p>Usually, the first thing to do is to read an XML input. The parser accepts
   5242 documents either from in-memory strings or from files.  The functions are
   5243 defined in "parser.h":</p>
   5244 <dl>
   5245   <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt>
   5246     <dd><p>Parse a null-terminated string containing the document.</p>
   5247     </dd>
   5248 </dl>
   5249 <dl>
   5250   <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt>
   5251     <dd><p>Parse an XML document contained in a (possibly compressed)
   5252       file.</p>
   5253     </dd>
   5254 </dl>
   5255 
   5256 <p>The parser returns a pointer to the document structure (or NULL in case of
   5257 failure).</p>
   5258 
   5259 <h3 id="Invoking1">Invoking the parser: the push method</h3>
   5260 
   5261 <p>In order for the application to keep the control when the document is
   5262 being fetched (which is common for GUI based programs) libxml2 provides a
   5263 push interface, too, as of version 1.8.3. Here are the interface
   5264 functions:</p>
   5265 <pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
   5266                                          void *user_data,
   5267                                          const char *chunk,
   5268                                          int size,
   5269                                          const char *filename);
   5270 int              xmlParseChunk          (xmlParserCtxtPtr ctxt,
   5271                                          const char *chunk,
   5272                                          int size,
   5273                                          int terminate);</pre>
   5274 
   5275 <p>and here is a simple example showing how to use the interface:</p>
   5276 <pre>            FILE *f;
   5277 
   5278             f = fopen(filename, "r");
   5279             if (f != NULL) {
   5280                 int res, size = 1024;
   5281                 char chars[1024];
   5282                 xmlParserCtxtPtr ctxt;
   5283 
   5284                 res = fread(chars, 1, 4, f);
   5285                 if (res &gt; 0) {
   5286                     ctxt = xmlCreatePushParserCtxt(NULL, NULL,
   5287                                 chars, res, filename);
   5288                     while ((res = fread(chars, 1, size, f)) &gt; 0) {
   5289                         xmlParseChunk(ctxt, chars, res, 0);
   5290                     }
   5291                     xmlParseChunk(ctxt, chars, 0, 1);
   5292                     doc = ctxt-&gt;myDoc;
   5293                     xmlFreeParserCtxt(ctxt);
   5294                 }
   5295             }</pre>
   5296 
   5297 <p>The HTML parser embedded into libxml2 also has a push interface; the
   5298 functions are just prefixed by "html" rather than "xml".</p>
   5299 
   5300 <h3 id="Invoking2">Invoking the parser: the SAX interface</h3>
   5301 
   5302 <p>The tree-building interface makes the parser memory-hungry, first loading
   5303 the document in memory and then building the tree itself. Reading a document
   5304 without building the tree is possible using the SAX interfaces (see SAX.h and
   5305 <a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James
   5306 Henstridge's documentation</a>). Note also that the push interface can be
   5307 limited to SAX: just use the two first arguments of
   5308 <code>xmlCreatePushParserCtxt()</code>.</p>
   5309 
   5310 <h3><a name="Building">Building a tree from scratch</a></h3>
   5311 
   5312 <p>The other way to get an XML tree in memory is by building it. Basically
   5313 there is a set of functions dedicated to building new elements. (These are
   5314 also described in &lt;libxml/tree.h&gt;.) For example, here is a piece of
   5315 code that produces the XML document used in the previous examples:</p>
   5316 <pre>    #include &lt;libxml/tree.h&gt;
   5317     xmlDocPtr doc;
   5318     xmlNodePtr tree, subtree;
   5319 
   5320     doc = xmlNewDoc("1.0");
   5321     doc-&gt;children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL);
   5322     xmlSetProp(doc-&gt;children, "prop1", "gnome is great");
   5323     xmlSetProp(doc-&gt;children, "prop2", "&amp; linux too");
   5324     tree = xmlNewChild(doc-&gt;children, NULL, "head", NULL);
   5325     subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome");
   5326     tree = xmlNewChild(doc-&gt;children, NULL, "chapter", NULL);
   5327     subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure");
   5328     subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ...");
   5329     subtree = xmlNewChild(tree, NULL, "image", NULL);
   5330     xmlSetProp(subtree, "href", "linus.gif");</pre>
   5331 
   5332 <p>Not really rocket science ...</p>
   5333 
   5334 <h3><a name="Traversing">Traversing the tree</a></h3>
   5335 
   5336 <p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your
   5337 code has access to the internal structure of all the elements of the tree.
   5338 The names should be somewhat simple like <strong>parent</strong>,
   5339 <strong>children</strong>, <strong>next</strong>, <strong>prev</strong>,
   5340 <strong>properties</strong>, etc... For example, still with the previous
   5341 example:</p>
   5342 <pre><code>doc-&gt;children-&gt;children-&gt;children</code></pre>
   5343 
   5344 <p>points to the title element,</p>
   5345 <pre>doc-&gt;children-&gt;children-&gt;next-&gt;children-&gt;children</pre>
   5346 
   5347 <p>points to the text node containing the chapter title "The Linux
   5348 adventure".</p>
   5349 
   5350 <p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be
   5351 present before the document root, so <code>doc-&gt;children</code> may point
   5352 to an element which is not the document Root Element; a function
   5353 <code>xmlDocGetRootElement()</code> was added for this purpose.</p>
   5354 
   5355 <h3><a name="Modifying">Modifying the tree</a></h3>
   5356 
   5357 <p>Functions are provided for reading and writing the document content. Here
   5358 is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p>
   5359 <dl>
   5360   <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const
   5361   xmlChar *value);</code></dt>
   5362     <dd><p>This sets (or changes) an attribute carried by an ELEMENT node.
   5363       The value can be NULL.</p>
   5364     </dd>
   5365 </dl>
   5366 <dl>
   5367   <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar
   5368   *name);</code></dt>
   5369     <dd><p>This function returns a pointer to new copy of the property
   5370       content. Note that the user must deallocate the result.</p>
   5371     </dd>
   5372 </dl>
   5373 
   5374 <p>Two functions are provided for reading and writing the text associated
   5375 with elements:</p>
   5376 <dl>
   5377   <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar
   5378   *value);</code></dt>
   5379     <dd><p>This function takes an "external" string and converts it to one
   5380       text node or possibly to a list of entity and text nodes. All
   5381       non-predefined entity references like &amp;Gnome; will be stored
   5382       internally as entity nodes, hence the result of the function may not be
   5383       a single node.</p>
   5384     </dd>
   5385 </dl>
   5386 <dl>
   5387   <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int
   5388   inLine);</code></dt>
   5389     <dd><p>This function is the inverse of
   5390       <code>xmlStringGetNodeList()</code>. It generates a new string
   5391       containing the content of the text and entity nodes. Note the extra
   5392       argument inLine. If this argument is set to 1, the function will expand
   5393       entity references.  For example, instead of returning the &amp;Gnome;
   5394       XML encoding in the string, it will substitute it with its value (say,
   5395       "GNU Network Object Model Environment").</p>
   5396     </dd>
   5397 </dl>
   5398 
   5399 <h3><a name="Saving">Saving a tree</a></h3>
   5400 
   5401 <p>Basically 3 options are possible:</p>
   5402 <dl>
   5403   <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int
   5404   *size);</code></dt>
   5405     <dd><p>Returns a buffer into which the document has been saved.</p>
   5406     </dd>
   5407 </dl>
   5408 <dl>
   5409   <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt>
   5410     <dd><p>Dumps a document to an open file descriptor.</p>
   5411     </dd>
   5412 </dl>
   5413 <dl>
   5414   <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt>
   5415     <dd><p>Saves the document to a file. In this case, the compression
   5416       interface is triggered if it has been turned on.</p>
   5417     </dd>
   5418 </dl>
   5419 
   5420 <h3><a name="Compressio">Compression</a></h3>
   5421 
   5422 <p>The library transparently handles compression when doing file-based
   5423 accesses. The level of compression on saves can be turned on either globally
   5424 or individually for one file:</p>
   5425 <dl>
   5426   <dt><code>int  xmlGetDocCompressMode (xmlDocPtr doc);</code></dt>
   5427     <dd><p>Gets the document compression ratio (0-9).</p>
   5428     </dd>
   5429 </dl>
   5430 <dl>
   5431   <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt>
   5432     <dd><p>Sets the document compression ratio.</p>
   5433     </dd>
   5434 </dl>
   5435 <dl>
   5436   <dt><code>int  xmlGetCompressMode(void);</code></dt>
   5437     <dd><p>Gets the default compression ratio.</p>
   5438     </dd>
   5439 </dl>
   5440 <dl>
   5441   <dt><code>void xmlSetCompressMode(int mode);</code></dt>
   5442     <dd><p>Sets the default compression ratio.</p>
   5443     </dd>
   5444 </dl>
   5445 
   5446 <h2><a name="Entities">Entities or no entities</a></h2>
   5447 
   5448 <p>Entities in principle are similar to simple C macros. An entity defines an
   5449 abbreviation for a given string that you can reuse many times throughout the
   5450 content of your document. Entities are especially useful when a given string
   5451 may occur frequently within a document, or to confine the change needed to a
   5452 document to a restricted area in the internal subset of the document (at the
   5453 beginning). Example:</p>
   5454 <pre>1 &lt;?xml version="1.0"?&gt;
   5455 2 &lt;!DOCTYPE EXAMPLE SYSTEM "example.dtd" [
   5456 3 &lt;!ENTITY xml "Extensible Markup Language"&gt;
   5457 4 ]&gt;
   5458 5 &lt;EXAMPLE&gt;
   5459 6    &amp;xml;
   5460 7 &lt;/EXAMPLE&gt;</pre>
   5461 
   5462 <p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing
   5463 its name with '&amp;' and following it by ';' without any spaces added. There
   5464 are 5 predefined entities in libxml2 allowing you to escape characters with
   5465 predefined meaning in some parts of the xml document content:
   5466 <strong>&amp;lt;</strong> for the character '&lt;', <strong>&amp;gt;</strong>
   5467 for the character '&gt;',  <strong>&amp;apos;</strong> for the character ''',
   5468 <strong>&amp;quot;</strong> for the character '"', and
   5469 <strong>&amp;amp;</strong> for the character '&amp;'.</p>
   5470 
   5471 <p>One of the problems related to entities is that you may want the parser to
   5472 substitute an entity's content so that you can see the replacement text in
   5473 your application. Or you may prefer to keep entity references as such in the
   5474 content to be able to save the document back without losing this usually
   5475 precious information (if the user went through the pain of explicitly
   5476 defining entities, he may have a a rather negative attitude if you blindly
   5477 substitute them as saving time). The <a
   5478 href="html/libxml-parser.html#xmlSubstituteEntitiesDefault">xmlSubstituteEntitiesDefault()</a>
   5479 function allows you to check and change the behaviour, which is to not
   5480 substitute entities by default.</p>
   5481 
   5482 <p>Here is the DOM tree built by libxml2 for the previous document in the
   5483 default case:</p>
   5484 <pre>/gnome/src/gnome-xml -&gt; ./xmllint --debug test/ent1
   5485 DOCUMENT
   5486 version=1.0
   5487    ELEMENT EXAMPLE
   5488      TEXT
   5489      content=
   5490      ENTITY_REF
   5491        INTERNAL_GENERAL_ENTITY xml
   5492        content=Extensible Markup Language
   5493      TEXT
   5494      content=</pre>
   5495 
   5496 <p>And here is the result when substituting entities:</p>
   5497 <pre>/gnome/src/gnome-xml -&gt; ./tester --debug --noent test/ent1
   5498 DOCUMENT
   5499 version=1.0
   5500    ELEMENT EXAMPLE
   5501      TEXT
   5502      content=     Extensible Markup Language</pre>
   5503 
   5504 <p>So, entities or no entities? Basically, it depends on your use case. I
   5505 suggest that you keep the non-substituting default behaviour and avoid using
   5506 entities in your XML document or data if you are not willing to handle the
   5507 entity references elements in the DOM tree.</p>
   5508 
   5509 <p>Note that at save time libxml2 enforces the conversion of the predefined
   5510 entities where necessary to prevent well-formedness problems, and will also
   5511 transparently replace those with chars (i.e. it will not generate entity
   5512 reference elements in the DOM tree or call the reference() SAX callback when
   5513 finding them in the input).</p>
   5514 
   5515 <p><span style="background-color: #FF0000">WARNING</span>: handling entities
   5516 on top of the libxml2 SAX interface is difficult!!! If you plan to use
   5517 non-predefined entities in your documents, then the learning curve to handle
   5518 then using the SAX API may be long. If you plan to use complex documents, I
   5519 strongly suggest you consider using the DOM interface instead and let libxml
   5520 deal with the complexity rather than trying to do it yourself.</p>
   5521 
   5522 <h2><a name="Namespaces">Namespaces</a></h2>
   5523 
   5524 <p>The libxml2 library implements <a
   5525 href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by
   5526 recognizing namespace constructs in the input, and does namespace lookup
   5527 automatically when building the DOM tree. A namespace declaration is
   5528 associated with an in-memory structure and all elements or attributes within
   5529 that namespace point to it. Hence testing the namespace is a simple and fast
   5530 equality operation at the user level.</p>
   5531 
   5532 <p>I suggest that people using libxml2 use a namespace, and declare it in the
   5533 root element of their document as the default namespace. Then they don't need
   5534 to use the prefix in the content but we will have a basis for future semantic
   5535 refinement and  merging of data from different sources. This doesn't increase
   5536 the size of the XML output significantly, but significantly increases its
   5537 value in the long-term. Example:</p>
   5538 <pre>&lt;mydoc xmlns="http://mydoc.example.org/schemas/"&gt;
   5539    &lt;elem1&gt;...&lt;/elem1&gt;
   5540    &lt;elem2&gt;...&lt;/elem2&gt;
   5541 &lt;/mydoc&gt;</pre>
   5542 
   5543 <p>The namespace value has to be an absolute URL, but the URL doesn't have to
   5544 point to any existing resource on the Web. It will bind all the element and
   5545 attributes with that URL. I suggest to use an URL within a domain you
   5546 control, and that the URL should contain some kind of version information if
   5547 possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a
   5548 good namespace scheme.</p>
   5549 
   5550 <p>Then when you load a file, make sure that a namespace carrying the
   5551 version-independent prefix is installed on the root element of your document,
   5552 and if the version information don't match something you know, warn the user
   5553 and be liberal in what you accept as the input. Also do *not* try to base
   5554 namespace checking on the prefix value. &lt;foo:text&gt; may be exactly the
   5555 same as &lt;bar:text&gt; in another document. What really matters is the URI
   5556 associated with the element or the attribute, not the prefix string (which is
   5557 just a shortcut for the full URI). In libxml, element and attributes have an
   5558 <code>ns</code> field pointing to an xmlNs structure detailing the namespace
   5559 prefix and its URI.</p>
   5560 
   5561 <p>@@Interfaces@@</p>
   5562 <pre>xmlNodePtr node;
   5563 if(!strncmp(node-&gt;name,"mytag",5)
   5564   &amp;&amp; node-&gt;ns
   5565   &amp;&amp; !strcmp(node-&gt;ns-&gt;href,"http://www.mysite.com/myns/1.0")) {
   5566   ...
   5567 }</pre>
   5568 
   5569 <p>Usually people object to using namespaces together with validity checking.
   5570 I will try to make sure that using namespaces won't break validity checking,
   5571 so even if you plan to use or currently are using validation I strongly
   5572 suggest adding namespaces to your document. A default namespace scheme
   5573 <code>xmlns="http://...."</code> should not break validity even on less
   5574 flexible parsers. Using namespaces to mix and differentiate content coming
   5575 from multiple DTDs will certainly break current validation schemes. To check
   5576 such documents one needs to use schema-validation, which is supported in
   5577 libxml2 as well. See <a href="http://www.relaxng.org/">relagx-ng</a> and <a
   5578 href="http://www.w3c.org/XML/Schema">w3c-schema</a>.</p>
   5579 
   5580 <h2><a name="Upgrading">Upgrading 1.x code</a></h2>
   5581 
   5582 <p>Incompatible changes:</p>
   5583 
   5584 <p>Version 2 of libxml2 is the first version introducing serious backward
   5585 incompatible changes. The main goals were:</p>
   5586 <ul>
   5587   <li>a general cleanup. A number of mistakes inherited from the very early
   5588     versions couldn't be changed due to compatibility constraints. Example
   5589     the "childs" element in the nodes.</li>
   5590   <li>Uniformization of the various nodes, at least for their header and link
   5591     parts (doc, parent, children, prev, next), the goal is a simpler
   5592     programming model and simplifying the task of the DOM implementors.</li>
   5593   <li>better conformances to the XML specification, for example version 1.x
   5594     had an heuristic to try to detect ignorable white spaces. As a result the
   5595     SAX event generated were ignorableWhitespace() while the spec requires
   5596     character() in that case. This also mean that a number of DOM node
   5597     containing blank text may populate the DOM tree which were not present
   5598     before.</li>
   5599 </ul>
   5600 
   5601 <h3>How to fix libxml-1.x code:</h3>
   5602 
   5603 <p>So client code of libxml designed to run with version 1.x may have to be
   5604 changed to compile against version 2.x of libxml. Here is a list of changes
   5605 that I have collected, they may not be sufficient, so in case you find other
   5606 change which are required, <a href="mailto:Daniel.Veillard (a] w3.org">drop me a
   5607 mail</a>:</p>
   5608 <ol>
   5609   <li>The package name have changed from libxml to libxml2, the library name
   5610     is now -lxml2 . There is a new xml2-config script which should be used to
   5611     select the right parameters libxml2</li>
   5612   <li>Node <strong>childs</strong> field has been renamed
   5613     <strong>children</strong> so s/childs/children/g should be  applied
   5614     (probability of having "childs" anywhere else is close to 0+</li>
   5615   <li>The document don't have anymore a <strong>root</strong> element it has
   5616     been replaced by <strong>children</strong> and usually you will get a
   5617     list of element here. For example a Dtd element for the internal subset
   5618     and it's declaration may be found in that list, as well as processing
   5619     instructions or comments found before or after the document root element.
   5620     Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of
   5621     a document. Alternatively if you are sure to not reference DTDs nor have
   5622     PIs or comments before or after the root element
   5623     s/-&gt;root/-&gt;children/g will probably do it.</li>
   5624   <li>The white space issue, this one is more complex, unless special case of
   5625     validating parsing, the line breaks and spaces usually used for indenting
   5626     and formatting the document content becomes significant. So they are
   5627     reported by SAX and if your using the DOM tree, corresponding nodes are
   5628     generated. Too approach can be taken:
   5629     <ol>
   5630       <li>lazy one, use the compatibility call
   5631         <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are
   5632         relying on a special (and possibly broken) set of heuristics of
   5633         libxml to detect ignorable blanks. Don't complain if it breaks or
   5634         make your application not 100% clean w.r.t. to it's input.</li>
   5635       <li>the Right Way: change you code to accept possibly insignificant
   5636         blanks characters, or have your tree populated with weird blank text
   5637         nodes. You can spot them using the commodity function
   5638         <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank
   5639         nodes.</li>
   5640     </ol>
   5641     <p>Note also that with the new default the output functions don't add any
   5642     extra indentation when saving a tree in order to be able to round trip
   5643     (read and save) without inflating the document with extra formatting
   5644     chars.</p>
   5645   </li>
   5646   <li>The include path has changed to $prefix/libxml/ and the includes
   5647     themselves uses this new prefix in includes instructions... If you are
   5648     using (as expected) the
   5649     <pre>xml2-config --cflags</pre>
   5650     <p>output to generate you compile commands this will probably work out of
   5651     the box</p>
   5652   </li>
   5653   <li>xmlDetectCharEncoding takes an extra argument indicating the length in
   5654     byte of the head of the document available for character detection.</li>
   5655 </ol>
   5656 
   5657 <h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3>
   5658 
   5659 <p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released
   5660 to allow smooth upgrade of existing libxml v1code while retaining
   5661 compatibility. They offers the following:</p>
   5662 <ol>
   5663   <li>similar include naming, one should use
   5664     <strong>#include&lt;libxml/...&gt;</strong> in both cases.</li>
   5665   <li>similar identifiers defined via macros for the child and root fields:
   5666     respectively <strong>xmlChildrenNode</strong> and
   5667     <strong>xmlRootNode</strong></li>
   5668   <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be
   5669     inserted once in the client code</li>
   5670 </ol>
   5671 
   5672 <p>So the roadmap to upgrade your existing libxml applications is the
   5673 following:</p>
   5674 <ol>
   5675   <li>install the  libxml-1.8.8 (and libxml-devel-1.8.8) packages</li>
   5676   <li>find all occurrences where the xmlDoc <strong>root</strong> field is
   5677     used and change it to <strong>xmlRootNode</strong></li>
   5678   <li>similarly find all occurrences where the xmlNode
   5679     <strong>childs</strong> field is used and change it to
   5680     <strong>xmlChildrenNode</strong></li>
   5681   <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your
   5682     <strong>main()</strong> or in the library init entry point</li>
   5683   <li>Recompile, check compatibility, it should still work</li>
   5684   <li>Change your configure script to look first for xml2-config and fall
   5685     back using xml-config . Use the --cflags and --libs output of the command
   5686     as the Include and Linking parameters needed to use libxml.</li>
   5687   <li>install libxml2-2.3.x and  libxml2-devel-2.3.x (libxml-1.8.y and
   5688     libxml-devel-1.8.y can be kept simultaneously)</li>
   5689   <li>remove your config.cache, relaunch your configuration mechanism, and
   5690     recompile, if steps 2 and 3 were done right it should compile as-is</li>
   5691   <li>Test that your application is still running correctly, if not this may
   5692     be due to extra empty nodes due to formating spaces being kept in libxml2
   5693     contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your
   5694     code before calling the parser (next to
   5695     <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li>
   5696 </ol>
   5697 
   5698 <p>Following those steps should work. It worked for some of my own code.</p>
   5699 
   5700 <p>Let me put some emphasis on the fact that there is far more changes from
   5701 libxml 1.x to 2.x than the ones you may have to patch for. The overall code
   5702 has been considerably cleaned up and the conformance to the XML specification
   5703 has been drastically improved too. Don't take those changes as an excuse to
   5704 not upgrade, it may cost a lot on the long term ...</p>
   5705 
   5706 <h2><a name="Thread">Thread safety</a></h2>
   5707 
   5708 <p>Starting with 2.4.7, libxml2 makes provisions to ensure that concurrent
   5709 threads can safely work in parallel parsing different documents. There is
   5710 however a couple of things to do to ensure it:</p>
   5711 <ul>
   5712   <li>configure the library accordingly using the --with-threads options</li>
   5713   <li>call xmlInitParser() in the "main" thread before using any of the
   5714     libxml2 API (except possibly selecting a different memory allocator)</li>
   5715 </ul>
   5716 
   5717 <p>Note that the thread safety cannot be ensured for multiple threads sharing
   5718 the same document, the locking must be done at the application level, libxml
   5719 exports a basic mutex and reentrant mutexes API in &lt;libxml/threads.h&gt;.
   5720 The parts of the library checked for thread safety are:</p>
   5721 <ul>
   5722   <li>concurrent loading</li>
   5723   <li>file access resolution</li>
   5724   <li>catalog access</li>
   5725   <li>catalog building</li>
   5726   <li>entities lookup/accesses</li>
   5727   <li>validation</li>
   5728   <li>global variables per-thread override</li>
   5729   <li>memory handling</li>
   5730 </ul>
   5731 
   5732 <p>XPath has been tested for threaded usage on non-modified document
   5733    for example when using libxslt, but make 100% sure the documents
   5734    are accessed read-only !</p>
   5735 
   5736 <h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2>
   5737 
   5738 <p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document
   5739 Object Model</em>; this is an API for accessing XML or HTML structured
   5740 documents. Native support for DOM in Gnome is on the way (module gnome-dom),
   5741 and will be based on gnome-xml. This will be a far cleaner interface to
   5742 manipulate XML files within Gnome since it won't expose the internal
   5743 structure.</p>
   5744 
   5745 <p>The current DOM implementation on top of libxml2 is the <a
   5746 href="http://svn.gnome.org/viewvc/gdome2/trunk/">gdome2 Gnome module</a>, this
   5747 is a full DOM interface, thanks to Paolo Casarini, check the <a
   5748 href="http://gdome2.cs.unibo.it/">Gdome2 homepage</a> for more
   5749 information.</p>
   5750 
   5751 <h2><a name="Example"></a><a name="real">A real example</a></h2>
   5752 
   5753 <p>Here is a real size example, where the actual content of the application
   5754 data is not kept in the DOM tree but uses internal structures. It is based on
   5755 a proposal to keep a database of jobs related to Gnome, with an XML based
   5756 storage structure. Here is an <a href="gjobs.xml">XML encoded jobs
   5757 base</a>:</p>
   5758 <pre>&lt;?xml version="1.0"?&gt;
   5759 &lt;gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"&gt;
   5760   &lt;gjob:Jobs&gt;
   5761 
   5762     &lt;gjob:Job&gt;
   5763       &lt;gjob:Project ID="3"/&gt;
   5764       &lt;gjob:Application&gt;GBackup&lt;/gjob:Application&gt;
   5765       &lt;gjob:Category&gt;Development&lt;/gjob:Category&gt;
   5766 
   5767       &lt;gjob:Update&gt;
   5768         &lt;gjob:Status&gt;Open&lt;/gjob:Status&gt;
   5769         &lt;gjob:Modified&gt;Mon, 07 Jun 1999 20:27:45 -0400 MET DST&lt;/gjob:Modified&gt;
   5770         &lt;gjob:Salary&gt;USD 0.00&lt;/gjob:Salary&gt;
   5771       &lt;/gjob:Update&gt;
   5772 
   5773       &lt;gjob:Developers&gt;
   5774         &lt;gjob:Developer&gt;
   5775         &lt;/gjob:Developer&gt;
   5776       &lt;/gjob:Developers&gt;
   5777 
   5778       &lt;gjob:Contact&gt;
   5779         &lt;gjob:Person&gt;Nathan Clemons&lt;/gjob:Person&gt;
   5780         &lt;gjob:Email&gt;nathan (a] windsofstorm.net&lt;/gjob:Email&gt;
   5781         &lt;gjob:Company&gt;
   5782         &lt;/gjob:Company&gt;
   5783         &lt;gjob:Organisation&gt;
   5784         &lt;/gjob:Organisation&gt;
   5785         &lt;gjob:Webpage&gt;
   5786         &lt;/gjob:Webpage&gt;
   5787         &lt;gjob:Snailmail&gt;
   5788         &lt;/gjob:Snailmail&gt;
   5789         &lt;gjob:Phone&gt;
   5790         &lt;/gjob:Phone&gt;
   5791       &lt;/gjob:Contact&gt;
   5792 
   5793       &lt;gjob:Requirements&gt;
   5794       The program should be released as free software, under the GPL.
   5795       &lt;/gjob:Requirements&gt;
   5796 
   5797       &lt;gjob:Skills&gt;
   5798       &lt;/gjob:Skills&gt;
   5799 
   5800       &lt;gjob:Details&gt;
   5801       A GNOME based system that will allow a superuser to configure 
   5802       compressed and uncompressed files and/or file systems to be backed 
   5803       up with a supported media in the system.  This should be able to 
   5804       perform via find commands generating a list of files that are passed 
   5805       to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine 
   5806       or via operations performed on the filesystem itself. Email 
   5807       notification and GUI status display very important.
   5808       &lt;/gjob:Details&gt;
   5809 
   5810     &lt;/gjob:Job&gt;
   5811 
   5812   &lt;/gjob:Jobs&gt;
   5813 &lt;/gjob:Helping&gt;</pre>
   5814 
   5815 <p>While loading the XML file into an internal DOM tree is a matter of
   5816 calling only a couple of functions, browsing the tree to gather the data and
   5817 generate the internal structures is harder, and more error prone.</p>
   5818 
   5819 <p>The suggested principle is to be tolerant with respect to the input
   5820 structure. For example, the ordering of the attributes is not significant,
   5821 the XML specification is clear about it. It's also usually a good idea not to
   5822 depend on the order of the children of a given node, unless it really makes
   5823 things harder. Here is some code to parse the information for a person:</p>
   5824 <pre>/*
   5825  * A person record
   5826  */
   5827 typedef struct person {
   5828     char *name;
   5829     char *email;
   5830     char *company;
   5831     char *organisation;
   5832     char *smail;
   5833     char *webPage;
   5834     char *phone;
   5835 } person, *personPtr;
   5836 
   5837 /*
   5838  * And the code needed to parse it
   5839  */
   5840 personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
   5841     personPtr ret = NULL;
   5842 
   5843 DEBUG("parsePerson\n");
   5844     /*
   5845      * allocate the struct
   5846      */
   5847     ret = (personPtr) malloc(sizeof(person));
   5848     if (ret == NULL) {
   5849         fprintf(stderr,"out of memory\n");
   5850         return(NULL);
   5851     }
   5852     memset(ret, 0, sizeof(person));
   5853 
   5854     /* We don't care what the top level element name is */
   5855     cur = cur-&gt;xmlChildrenNode;
   5856     while (cur != NULL) {
   5857         if ((!strcmp(cur-&gt;name, "Person")) &amp;&amp; (cur-&gt;ns == ns))
   5858             ret-&gt;name = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
   5859         if ((!strcmp(cur-&gt;name, "Email")) &amp;&amp; (cur-&gt;ns == ns))
   5860             ret-&gt;email = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
   5861         cur = cur-&gt;next;
   5862     }
   5863 
   5864     return(ret);
   5865 }</pre>
   5866 
   5867 <p>Here are a couple of things to notice:</p>
   5868 <ul>
   5869   <li>Usually a recursive parsing style is the more convenient one: XML data
   5870     is by nature subject to repetitive constructs and usually exhibits highly
   5871     structured patterns.</li>
   5872   <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>,
   5873     i.e. the pointer to the global XML document and the namespace reserved to
   5874     the application. Document wide information are needed for example to
   5875     decode entities and it's a good coding practice to define a namespace for
   5876     your application set of data and test that the element and attributes
   5877     you're analyzing actually pertains to your application space. This is
   5878     done by a simple equality test (cur-&gt;ns == ns).</li>
   5879   <li>To retrieve text and attributes value, you can use the function
   5880     <em>xmlNodeListGetString</em> to gather all the text and entity reference
   5881     nodes generated by the DOM output and produce an single text string.</li>
   5882 </ul>
   5883 
   5884 <p>Here is another piece of code used to parse another level of the
   5885 structure:</p>
   5886 <pre>#include &lt;libxml/tree.h&gt;
   5887 /*
   5888  * a Description for a Job
   5889  */
   5890 typedef struct job {
   5891     char *projectID;
   5892     char *application;
   5893     char *category;
   5894     personPtr contact;
   5895     int nbDevelopers;
   5896     personPtr developers[100]; /* using dynamic alloc is left as an exercise */
   5897 } job, *jobPtr;
   5898 
   5899 /*
   5900  * And the code needed to parse it
   5901  */
   5902 jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) {
   5903     jobPtr ret = NULL;
   5904 
   5905 DEBUG("parseJob\n");
   5906     /*
   5907      * allocate the struct
   5908      */
   5909     ret = (jobPtr) malloc(sizeof(job));
   5910     if (ret == NULL) {
   5911         fprintf(stderr,"out of memory\n");
   5912         return(NULL);
   5913     }
   5914     memset(ret, 0, sizeof(job));
   5915 
   5916     /* We don't care what the top level element name is */
   5917     cur = cur-&gt;xmlChildrenNode;
   5918     while (cur != NULL) {
   5919         
   5920         if ((!strcmp(cur-&gt;name, "Project")) &amp;&amp; (cur-&gt;ns == ns)) {
   5921             ret-&gt;projectID = xmlGetProp(cur, "ID");
   5922             if (ret-&gt;projectID == NULL) {
   5923                 fprintf(stderr, "Project has no ID\n");
   5924             }
   5925         }
   5926         if ((!strcmp(cur-&gt;name, "Application")) &amp;&amp; (cur-&gt;ns == ns))
   5927             ret-&gt;application = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
   5928         if ((!strcmp(cur-&gt;name, "Category")) &amp;&amp; (cur-&gt;ns == ns))
   5929             ret-&gt;category = xmlNodeListGetString(doc, cur-&gt;xmlChildrenNode, 1);
   5930         if ((!strcmp(cur-&gt;name, "Contact")) &amp;&amp; (cur-&gt;ns == ns))
   5931             ret-&gt;contact = parsePerson(doc, ns, cur);
   5932         cur = cur-&gt;next;
   5933     }
   5934 
   5935     return(ret);
   5936 }</pre>
   5937 
   5938 <p>Once you are used to it, writing this kind of code is quite simple, but
   5939 boring. Ultimately, it could be possible to write stubbers taking either C
   5940 data structure definitions, a set of XML examples or an XML DTD and produce
   5941 the code needed to import and export the content between C data and XML
   5942 storage. This is left as an exercise to the reader :-)</p>
   5943 
   5944 <p>Feel free to use <a href="example/gjobread.c">the code for the full C
   5945 parsing example</a> as a template, it is also available with Makefile in the
   5946 Gnome SVN base under libxml2/example</p>
   5947 
   5948 <h2><a name="Contributi">Contributions</a></h2>
   5949 <ul>
   5950   <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of
   5951     patches, Gary Pennington worked on the validation API, threading support
   5952     and Solaris port.</li>
   5953   <li>John Fleck helps maintaining the documentation and man pages.</li>
   5954   <li><a href="mailto:igor (a] zlatkovic.com">Igor  Zlatkovic</a> is now the
   5955     maintainer of the Windows port, <a
   5956     href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
   5957     binaries</a></li>
   5958   <li><a href="mailto:Gary.Pennington (a] sun.com">Gary Pennington</a> provides
   5959     <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li>
   5960   <li><a
   5961     href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt
   5962     Sergeant</a> developed <a
   5963     href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for
   5964     libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML
   5965     application server</a></li>
   5966   <li><a href="mailto:fnatter (a] gmx.net">Felix Natter</a> and <a
   5967     href="mailto:geertk (a] ai.rug.nl">Geert Kloosterman</a> provide <a
   5968     href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions
   5969     documentation</li>
   5970   <li><a href="mailto:sherwin (a] nlm.nih.gov">Ziying Sherwin</a> provided <a
   5971     href="http://xmlsoft.org/messages/0488.html">man pages</a></li>
   5972   <li>there is a module for <a
   5973     href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support
   5974     in OpenNSD/AOLServer</a></li>
   5975   <li><a href="mailto:dkuhlman (a] cutter.rexx.com">Dave Kuhlman</a> provided the
   5976     first version of libxml/libxslt <a
   5977     href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li>
   5978   <li>Petr Kozelka provides <a
   5979     href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue
   5980     libxml2</a> with Kylix and Delphi and other Pascal compilers</li>
   5981   <li><a href="mailto:aleksey (a] aleksey.com">Aleksey Sanin</a> implemented the
   5982     <a href="http://www.w3.org/Signature/">XML Canonicalization and XML
   5983     Digital Signature</a> <a
   5984     href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li>
   5985   <li><a href="mailto:Steve.Ball (a] explain.com.au">Steve Ball</a> and
   5986     contributors maintain <a href="http://tclxml.sourceforge.net/">tcl
   5987     bindings for libxml2 and libxslt</a>, as well as <a
   5988     href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for
   5989     xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a>
   5990     a GUI for xsltproc.</li>
   5991 </ul>
   5992 
   5993 <p></p>
   5994 </body>
   5995 </html>
   5996