// Copyright (c) 2010 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "chrome/browser/extensions/extension_i18n_api.h" #include "base/string_piece.h" #include "base/utf_string_conversions.h" #include "chrome/browser/prefs/pref_service.h" #include "chrome/browser/profiles/profile.h" #include "chrome/common/pref_names.h" // Errors. static const char kEmptyAcceptLanguagesError[] = "accept-languages is empty."; bool GetAcceptLanguagesFunction::RunImpl() { string16 acceptLanguages = UTF8ToUTF16(profile()->GetPrefs()->GetString(prefs::kAcceptLanguages)); // Currently, there are 2 ways to set browser's accept-languages: through UI // or directly modify the preference file. The accept-languages set through // UI is guranteed to be valid, and the accept-languages string returned from // profile()->GetPrefs()->GetString(prefs::kAcceptLanguages) is guranteed to // be valid and well-formed, which means each accept-langauge is a valid // code, and accept-languages are seperatd by "," without surrrounding // spaces. But we do not do any validation (either the format or the validity // of the language code) on accept-languages set through editing preference // file directly. So, here, we're adding extra checks to be resistant to // crashes caused by data corruption. result_.reset(new ListValue()); if (acceptLanguages.empty()) { error_ = kEmptyAcceptLanguagesError; return false; } size_t begin = 0; size_t end; while (1) { end = acceptLanguages.find(',', begin); if (end > begin) { // Guard against a malformed value with multiple "," in a row. string16 acceptLang = acceptLanguages.substr(begin, end - begin); static_cast<ListValue*>(result_.get())-> Append(Value::CreateStringValue(acceptLang)); } begin = end + 1; // 'begin >= acceptLanguages.length()' to guard against a value // ending with ','. if (end == string16::npos || begin >= acceptLanguages.length()) break; } if (static_cast<ListValue*>(result_.get())->GetSize() == 0) { error_ = kEmptyAcceptLanguagesError; return false; } return true; }