1 // Copyright (c) 2010 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "chrome/browser/extensions/extension_i18n_api.h" 6 7 #include "base/string_piece.h" 8 #include "base/utf_string_conversions.h" 9 #include "chrome/browser/prefs/pref_service.h" 10 #include "chrome/browser/profiles/profile.h" 11 #include "chrome/common/pref_names.h" 12 13 // Errors. 14 static const char kEmptyAcceptLanguagesError[] = "accept-languages is empty."; 15 16 bool GetAcceptLanguagesFunction::RunImpl() { 17 string16 acceptLanguages = 18 UTF8ToUTF16(profile()->GetPrefs()->GetString(prefs::kAcceptLanguages)); 19 // Currently, there are 2 ways to set browser's accept-languages: through UI 20 // or directly modify the preference file. The accept-languages set through 21 // UI is guranteed to be valid, and the accept-languages string returned from 22 // profile()->GetPrefs()->GetString(prefs::kAcceptLanguages) is guranteed to 23 // be valid and well-formed, which means each accept-langauge is a valid 24 // code, and accept-languages are seperatd by "," without surrrounding 25 // spaces. But we do not do any validation (either the format or the validity 26 // of the language code) on accept-languages set through editing preference 27 // file directly. So, here, we're adding extra checks to be resistant to 28 // crashes caused by data corruption. 29 result_.reset(new ListValue()); 30 if (acceptLanguages.empty()) { 31 error_ = kEmptyAcceptLanguagesError; 32 return false; 33 } 34 size_t begin = 0; 35 size_t end; 36 while (1) { 37 end = acceptLanguages.find(',', begin); 38 if (end > begin) { 39 // Guard against a malformed value with multiple "," in a row. 40 string16 acceptLang = acceptLanguages.substr(begin, end - begin); 41 static_cast<ListValue*>(result_.get())-> 42 Append(Value::CreateStringValue(acceptLang)); 43 } 44 begin = end + 1; 45 // 'begin >= acceptLanguages.length()' to guard against a value 46 // ending with ','. 47 if (end == string16::npos || begin >= acceptLanguages.length()) 48 break; 49 } 50 if (static_cast<ListValue*>(result_.get())->GetSize() == 0) { 51 error_ = kEmptyAcceptLanguagesError; 52 return false; 53 } 54 return true; 55 } 56
