Source/core/xml/parser/XMLDocumentParser.cpp

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This source file includes following definitions.
toString
toString
toAtomicString
toAtomicString
hasNoStyleInformation
m_defaultedCount
call
call
m_length
call
m_data
call
call
call
m_systemID
call
m_columnNumber
call
pushCurrentNode
popCurrentNode
clearCurrentNodeStack
insert
append
handleError
enterText
exitText
detach
end
finish
insertErrorMessageBlock
notifyFinished
isWaitingForScripts
pauseParsing
parseDocumentFragment
matchFunc
setAttributes
switchEncoding
parseChunk
finishParsing
isLibxmlDefaultCatalogFile
shouldAllowExternalLoad
openFunc
readFunc
writeFunc
closeFunc
errorFunc
initializeLibXMLIfNecessary
createStringParser
createMemoryParser
supportsXMLVersion
m_parsingFragment
m_parsingFragment
doWrite
handleNamespaceAttributes
handleElementAttributes
startElementNs
endElementNs
characters
error
processingInstruction
cdataBlock
comment
startDocument
endDocument
internalSubset
getParser
startElementNsHandler
endElementNsHandler
charactersHandler
processingInstructionHandler
cdataBlockHandler
commentHandler
WTF_ATTRIBUTE_PRINTF
WTF_ATTRIBUTE_PRINTF
WTF_ATTRIBUTE_PRINTF
sharedXHTMLEntity
convertUTF16EntityToUTF8
getXHTMLEntity
getEntityHandler
startDocumentHandler
endDocumentHandler
internalSubsetHandler
externalSubsetHandler
ignorableWhitespaceHandler
initializeParserContext
doEnd
xmlDocPtrForString
lineNumber
columnNumber
textPosition
stopParsing
resumeParsing
appendFragmentSource
attributesStartElementNsHandler
parseAttributes
/*
 * Copyright (C) 2000 Peter Kelly (pmk@post.com)
 * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
 * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 * Copyright (C) 2008 Holger Hans Peter Freyther
 * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "core/xml/parser/XMLDocumentParser.h"

#include <libxml/catalog.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <libxslt/xslt.h>
#include "FetchInitiatorTypeNames.h"
#include "HTMLNames.h"
#include "RuntimeEnabledFeatures.h"
#include "XMLNSNames.h"
#include "bindings/v8/ExceptionState.h"
#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "bindings/v8/ScriptController.h"
#include "bindings/v8/ScriptSourceCode.h"
#include "core/dom/CDATASection.h"
#include "core/dom/Comment.h"
#include "core/dom/Document.h"
#include "core/dom/DocumentFragment.h"
#include "core/dom/DocumentType.h"
#include "core/dom/ProcessingInstruction.h"
#include "core/dom/ScriptLoader.h"
#include "core/dom/TransformSource.h"
#include "core/fetch/ResourceFetcher.h"
#include "core/fetch/ScriptResource.h"
#include "core/frame/LocalFrame.h"
#include "core/frame/UseCounter.h"
#include "core/html/HTMLHtmlElement.h"
#include "core/html/HTMLTemplateElement.h"
#include "core/html/parser/HTMLEntityParser.h"
#include "core/html/parser/TextResourceDecoder.h"
#include "core/loader/FrameLoader.h"
#include "core/loader/ImageLoader.h"
#include "core/xml/XMLTreeViewer.h"
#include "core/xml/parser/SharedBufferReader.h"
#include "core/xml/parser/XMLDocumentParserScope.h"
#include "core/xml/parser/XMLParserInput.h"
#include "platform/SharedBuffer.h"
#include "platform/network/ResourceError.h"
#include "platform/network/ResourceRequest.h"
#include "platform/network/ResourceResponse.h"
#include "platform/weborigin/SecurityOrigin.h"
#include "wtf/StringExtras.h"
#include "wtf/TemporaryChange.h"
#include "wtf/Threading.h"
#include "wtf/Vector.h"
#include "wtf/unicode/UTF8.h"

using namespace std;

namespace WebCore {

using namespace HTMLNames;

// FIXME: HTMLConstructionSite has a limit of 512, should these match?
static const unsigned maxXMLTreeDepth = 5000;

static inline String toString(const xmlChar* string, size_t length)
{
    return String::fromUTF8(reinterpret_cast<const char*>(string), length);
}

static inline String toString(const xmlChar* string)
{
    return String::fromUTF8(reinterpret_cast<const char*>(string));
}

static inline AtomicString toAtomicString(const xmlChar* string, size_t length)
{
    return AtomicString::fromUTF8(reinterpret_cast<const char*>(string), length);
}

static inline AtomicString toAtomicString(const xmlChar* string)
{
    return AtomicString::fromUTF8(reinterpret_cast<const char*>(string));
}

static inline bool hasNoStyleInformation(Document* document)
{
    if (document->sawElementsInKnownNamespaces() || document->transformSourceDocument())
        return false;

    if (!document->frame() || !document->frame()->page())
        return false;

    if (document->frame()->tree().parent())
        return false; // This document is not in a top frame

    return true;
}

class PendingStartElementNSCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    PendingStartElementNSCallback(const AtomicString& localName, const AtomicString& prefix, const AtomicString& uri,
        int namespaceCount, const xmlChar** namespaces, int attributeCount, int defaultedCount, const xmlChar** attributes)
        : m_localName(localName)
        , m_prefix(prefix)
        , m_uri(uri)
        , m_namespaceCount(namespaceCount)
        , m_attributeCount(attributeCount)
        , m_defaultedCount(defaultedCount)
    {
        m_namespaces = static_cast<xmlChar**>(xmlMalloc(sizeof(xmlChar*) * namespaceCount * 2));
        for (int i = 0; i < namespaceCount * 2 ; i++)
            m_namespaces[i] = xmlStrdup(namespaces[i]);
        m_attributes = static_cast<xmlChar**>(xmlMalloc(sizeof(xmlChar*) * attributeCount * 5));
        for (int i = 0; i < attributeCount; i++) {
            // Each attribute has 5 elements in the array:
            // name, prefix, uri, value and an end pointer.
            for (int j = 0; j < 3; j++)
                m_attributes[i * 5 + j] = xmlStrdup(attributes[i * 5 + j]);
            int length = attributes[i * 5 + 4] - attributes[i * 5 + 3];
            m_attributes[i * 5 + 3] = xmlStrndup(attributes[i * 5 + 3], length);
            m_attributes[i * 5 + 4] = m_attributes[i * 5 + 3] + length;
        }
    }

    virtual ~PendingStartElementNSCallback()
    {
        for (int i = 0; i < m_namespaceCount * 2; i++)
            xmlFree(m_namespaces[i]);
        xmlFree(m_namespaces);
        for (int i = 0; i < m_attributeCount; i++)
            for (int j = 0; j < 4; j++)
                xmlFree(m_attributes[i * 5 + j]);
        xmlFree(m_attributes);
    }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->startElementNs(m_localName, m_prefix, m_uri,
                                  m_namespaceCount, const_cast<const xmlChar**>(m_namespaces),
                                  m_attributeCount, m_defaultedCount, const_cast<const xmlChar**>(m_attributes));
    }

private:
    AtomicString m_localName;
    AtomicString m_prefix;
    AtomicString m_uri;
    int m_namespaceCount;
    xmlChar** m_namespaces;
    int m_attributeCount;
    int m_defaultedCount;
    xmlChar** m_attributes;
};

class PendingEndElementNSCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->endElementNs();
    }
};

class PendingCharactersCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    PendingCharactersCallback(const xmlChar* chars, int length)
        : m_chars(xmlStrndup(chars, length))
        , m_length(length)
    {
    }

    virtual ~PendingCharactersCallback()
    {
        xmlFree(m_chars);
    }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->characters(m_chars, m_length);
    }

private:
    xmlChar* m_chars;
    int m_length;
};

class PendingProcessingInstructionCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    PendingProcessingInstructionCallback(const String& target, const String& data)
        : m_target(target)
        , m_data(data)
    {
    }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->processingInstruction(m_target, m_data);
    }

private:
    String m_target;
    String m_data;
};

class PendingCDATABlockCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    explicit PendingCDATABlockCallback(const String& text) : m_text(text) { }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->cdataBlock(m_text);
    }

private:
    String m_text;
};

class PendingCommentCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    explicit PendingCommentCallback(const String& text) : m_text(text) { }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->comment(m_text);
    }

private:
    String m_text;
};

class PendingInternalSubsetCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    PendingInternalSubsetCallback(const String& name, const String& externalID, const String& systemID)
        : m_name(name)
        , m_externalID(externalID)
        , m_systemID(systemID)
    {
    }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->internalSubset(m_name, m_externalID, m_systemID);
    }

private:
    String m_name;
    String m_externalID;
    String m_systemID;
};

class PendingErrorCallback FINAL : public XMLDocumentParser::PendingCallback {
public:
    PendingErrorCallback(XMLErrors::ErrorType type, const xmlChar* message, OrdinalNumber lineNumber, OrdinalNumber columnNumber)
        : m_type(type)
        , m_message(xmlStrdup(message))
        , m_lineNumber(lineNumber)
        , m_columnNumber(columnNumber)
    {
    }

    virtual ~PendingErrorCallback()
    {
        xmlFree(m_message);
    }

    virtual void call(XMLDocumentParser* parser) OVERRIDE
    {
        parser->handleError(m_type, reinterpret_cast<char*>(m_message), TextPosition(m_lineNumber, m_columnNumber));
    }

private:
    XMLErrors::ErrorType m_type;
    xmlChar* m_message;
    OrdinalNumber m_lineNumber;
    OrdinalNumber m_columnNumber;
};

void XMLDocumentParser::pushCurrentNode(ContainerNode* n)
{
    ASSERT(n);
    ASSERT(m_currentNode);
    if (n != document())
        n->ref();
    m_currentNodeStack.append(m_currentNode);
    m_currentNode = n;
    if (m_currentNodeStack.size() > maxXMLTreeDepth)
        handleError(XMLErrors::fatal, "Excessive node nesting.", textPosition());
}

void XMLDocumentParser::popCurrentNode()
{
    if (!m_currentNode)
        return;
    ASSERT(m_currentNodeStack.size());

    if (m_currentNode != document())
        m_currentNode->deref();

    m_currentNode = m_currentNodeStack.last();
    m_currentNodeStack.removeLast();
}

void XMLDocumentParser::clearCurrentNodeStack()
{
    if (m_currentNode && m_currentNode != document())
        m_currentNode->deref();
    m_currentNode = 0;
    m_leafTextNode = nullptr;

    if (m_currentNodeStack.size()) { // Aborted parsing.
        for (size_t i = m_currentNodeStack.size() - 1; i != 0; --i)
            m_currentNodeStack[i]->deref();
        if (m_currentNodeStack[0] && m_currentNodeStack[0] != document())
            m_currentNodeStack[0]->deref();
        m_currentNodeStack.clear();
    }
}

void XMLDocumentParser::insert(const SegmentedString&)
{
    ASSERT_NOT_REACHED();
}

void XMLDocumentParser::append(PassRefPtr<StringImpl> inputSource)
{
    SegmentedString source(inputSource);
    if (m_sawXSLTransform || !m_sawFirstElement)
        m_originalSourceForTransform.append(source);

    if (isStopped() || m_sawXSLTransform)
        return;

    if (m_parserPaused) {
        m_pendingSrc.append(source);
        return;
    }

    // JavaScript can detach the parser. Make sure this is not released
    // before the end of this method.
    RefPtr<XMLDocumentParser> protect(this);

    doWrite(source.toString());
}

void XMLDocumentParser::handleError(XMLErrors::ErrorType type, const char* formattedMessage, TextPosition position)
{
    m_xmlErrors.handleError(type, formattedMessage, position);
    if (type != XMLErrors::warning)
        m_sawError = true;
    if (type == XMLErrors::fatal)
        stopParsing();
}

void XMLDocumentParser::enterText()
{
    ASSERT(m_bufferedText.size() == 0);
    ASSERT(!m_leafTextNode);
    m_leafTextNode = Text::create(m_currentNode->document(), "");
    m_currentNode->parserAppendChild(m_leafTextNode.get());
}

void XMLDocumentParser::exitText()
{
    if (isStopped())
        return;

    if (!m_leafTextNode)
        return;

    m_leafTextNode->appendData(toString(m_bufferedText.data(), m_bufferedText.size()));
    m_bufferedText.clear();
    m_leafTextNode = nullptr;
}

void XMLDocumentParser::detach()
{
    clearCurrentNodeStack();
    ScriptableDocumentParser::detach();
}

void XMLDocumentParser::end()
{
    // XMLDocumentParserLibxml2 will do bad things to the document if doEnd() is called.
    // I don't believe XMLDocumentParserQt needs doEnd called in the fragment case.
    ASSERT(!m_parsingFragment);

    doEnd();

    // doEnd() call above can detach the parser and null out its document.
    // In that case, we just bail out.
    if (isDetached())
        return;

    // doEnd() could process a script tag, thus pausing parsing.
    if (m_parserPaused)
        return;

    if (m_sawError)
        insertErrorMessageBlock();
    else {
        exitText();
        document()->styleResolverChanged(RecalcStyleImmediately);
    }

    if (isParsing())
        prepareToStopParsing();
    document()->setReadyState(Document::Interactive);
    clearCurrentNodeStack();
    document()->finishedParsing();
}

void XMLDocumentParser::finish()
{
    // FIXME: We should ASSERT(!m_parserStopped) here, since it does not
    // makes sense to call any methods on DocumentParser once it's been stopped.
    // However, FrameLoader::stop calls DocumentParser::finish unconditionally.

    if (m_parserPaused)
        m_finishCalled = true;
    else
        end();
}

void XMLDocumentParser::insertErrorMessageBlock()
{
    m_xmlErrors.insertErrorMessageBlock();
}

void XMLDocumentParser::notifyFinished(Resource* unusedResource)
{
    ASSERT_UNUSED(unusedResource, unusedResource == m_pendingScript);

    ScriptSourceCode sourceCode(m_pendingScript.get());
    bool errorOccurred = m_pendingScript->errorOccurred();
    bool wasCanceled = m_pendingScript->wasCanceled();

    m_pendingScript->removeClient(this);
    m_pendingScript = 0;

    RefPtr<Element> e = m_scriptElement;
    m_scriptElement = nullptr;

    ScriptLoader* scriptLoader = toScriptLoaderIfPossible(e.get());
    ASSERT(scriptLoader);

    // JavaScript can detach this parser, make sure it's kept alive even if detached.
    RefPtr<XMLDocumentParser> protect(this);

    if (errorOccurred)
        scriptLoader->dispatchErrorEvent();
    else if (!wasCanceled) {
        scriptLoader->executeScript(sourceCode);
        scriptLoader->dispatchLoadEvent();
    }

    m_scriptElement = nullptr;

    if (!isDetached() && !m_requestingScript)
        resumeParsing();
}

bool XMLDocumentParser::isWaitingForScripts() const
{
    return m_pendingScript;
}

void XMLDocumentParser::pauseParsing()
{
    if (m_parsingFragment)
        return;

    m_parserPaused = true;
}

bool XMLDocumentParser::parseDocumentFragment(const String& chunk, DocumentFragment* fragment, Element* contextElement, ParserContentPolicy parserContentPolicy)
{
    if (!chunk.length())
        return true;

    // FIXME: We need to implement the HTML5 XML Fragment parsing algorithm:
    // http://www.whatwg.org/specs/web-apps/current-work/multipage/the-xhtml-syntax.html#xml-fragment-parsing-algorithm
    // For now we have a hack for script/style innerHTML support:
    if (contextElement && (contextElement->hasLocalName(HTMLNames::scriptTag) || contextElement->hasLocalName(HTMLNames::styleTag))) {
        fragment->parserAppendChild(fragment->document().createTextNode(chunk));
        return true;
    }

    RefPtr<XMLDocumentParser> parser = XMLDocumentParser::create(fragment, contextElement, parserContentPolicy);
    bool wellFormed = parser->appendFragmentSource(chunk);
    // Do not call finish().  Current finish() and doEnd() implementations touch the main Document/loader
    // and can cause crashes in the fragment case.
    parser->detach(); // Allows ~DocumentParser to assert it was detached before destruction.
    return wellFormed; // appendFragmentSource()'s wellFormed is more permissive than wellFormed().
}

static int globalDescriptor = 0;
static ThreadIdentifier libxmlLoaderThread = 0;

static int matchFunc(const char*)
{
    // Only match loads initiated due to uses of libxml2 from within XMLDocumentParser to avoid
    // interfering with client applications that also use libxml2.  http://bugs.webkit.org/show_bug.cgi?id=17353
    return XMLDocumentParserScope::currentFetcher && currentThread() == libxmlLoaderThread;
}

static inline void setAttributes(Element* element, Vector<Attribute>& attributeVector, ParserContentPolicy parserContentPolicy)
{
    if (!scriptingContentIsAllowed(parserContentPolicy))
        element->stripScriptingAttributes(attributeVector);
    element->parserSetAttributes(attributeVector);
}

static void switchEncoding(xmlParserCtxtPtr ctxt, bool is8Bit)
{
    // Hack around libxml2's lack of encoding overide support by manually
    // resetting the encoding to UTF-16 before every chunk.  Otherwise libxml
    // will detect <?xml version="1.0" encoding="<encoding name>"?> blocks
    // and switch encodings, causing the parse to fail.
    if (is8Bit) {
        xmlSwitchEncoding(ctxt, XML_CHAR_ENCODING_8859_1);
        return;
    }

    const UChar BOM = 0xFEFF;
    const unsigned char BOMHighByte = *reinterpret_cast<const unsigned char*>(&BOM);
    xmlSwitchEncoding(ctxt, BOMHighByte == 0xFF ? XML_CHAR_ENCODING_UTF16LE : XML_CHAR_ENCODING_UTF16BE);
}

static void parseChunk(xmlParserCtxtPtr ctxt, const String& chunk)
{
    bool is8Bit = chunk.is8Bit();
    switchEncoding(ctxt, is8Bit);
    if (is8Bit)
        xmlParseChunk(ctxt, reinterpret_cast<const char*>(chunk.characters8()), sizeof(LChar) * chunk.length(), 0);
    else
        xmlParseChunk(ctxt, reinterpret_cast<const char*>(chunk.characters16()), sizeof(UChar) * chunk.length(), 0);
}

static void finishParsing(xmlParserCtxtPtr ctxt)
{
    xmlParseChunk(ctxt, 0, 0, 1);
}

#define xmlParseChunk #error "Use parseChunk instead to select the correct encoding."

static bool isLibxmlDefaultCatalogFile(const String& urlString)
{
    // On non-Windows platforms libxml asks for this URL, the
    // "XML_XML_DEFAULT_CATALOG", on initialization.
    if (urlString == "file:///etc/xml/catalog")
        return true;

    // On Windows, libxml computes a URL relative to where its DLL resides.
    if (urlString.startsWith("file:///", false) && urlString.endsWith("/etc/catalog", false))
        return true;
    return false;
}

static bool shouldAllowExternalLoad(const KURL& url)
{
    String urlString = url.string();

    // This isn't really necessary now that initializeLibXMLIfNecessary
    // disables catalog support in libxml, but keeping it for defense in depth.
    if (isLibxmlDefaultCatalogFile(url))
        return false;

    // The most common DTD.  There isn't much point in hammering www.w3c.org
    // by requesting this URL for every XHTML document.
    if (urlString.startsWith("http://www.w3.org/TR/xhtml", false))
        return false;

    // Similarly, there isn't much point in requesting the SVG DTD.
    if (urlString.startsWith("http://www.w3.org/Graphics/SVG", false))
        return false;

    // The libxml doesn't give us a lot of context for deciding whether to
    // allow this request.  In the worst case, this load could be for an
    // external entity and the resulting document could simply read the
    // retrieved content.  If we had more context, we could potentially allow
    // the parser to load a DTD.  As things stand, we take the conservative
    // route and allow same-origin requests only.
    if (!XMLDocumentParserScope::currentFetcher->document()->securityOrigin()->canRequest(url)) {
        XMLDocumentParserScope::currentFetcher->printAccessDeniedMessage(url);
        return false;
    }

    return true;
}

static void* openFunc(const char* uri)
{
    ASSERT(XMLDocumentParserScope::currentFetcher);
    ASSERT(currentThread() == libxmlLoaderThread);

    KURL url(KURL(), uri);

    if (!shouldAllowExternalLoad(url))
        return &globalDescriptor;

    KURL finalURL;
    RefPtr<SharedBuffer> data;

    {
        ResourceFetcher* fetcher = XMLDocumentParserScope::currentFetcher;
        XMLDocumentParserScope scope(0);
        // FIXME: We should restore the original global error handler as well.

        if (fetcher->frame()) {
            FetchRequest request(ResourceRequest(url), FetchInitiatorTypeNames::xml, ResourceFetcher::defaultResourceOptions());
            ResourcePtr<Resource> resource = fetcher->fetchSynchronously(request);
            if (resource && !resource->errorOccurred()) {
                data = resource->resourceBuffer();
                finalURL = resource->response().url();
            }
        }
    }

    // We have to check the URL again after the load to catch redirects.
    // See <https://bugs.webkit.org/show_bug.cgi?id=21963>.
    if (!shouldAllowExternalLoad(finalURL))
        return &globalDescriptor;

    return new SharedBufferReader(data);
}

static int readFunc(void* context, char* buffer, int len)
{
    // Do 0-byte reads in case of a null descriptor
    if (context == &globalDescriptor)
        return 0;

    SharedBufferReader* data = static_cast<SharedBufferReader*>(context);
    return data->readData(buffer, len);
}

static int writeFunc(void*, const char*, int)
{
    // Always just do 0-byte writes
    return 0;
}

static int closeFunc(void* context)
{
    if (context != &globalDescriptor) {
        SharedBufferReader* data = static_cast<SharedBufferReader*>(context);
        delete data;
    }
    return 0;
}

static void errorFunc(void*, const char*, ...)
{
    // FIXME: It would be nice to display error messages somewhere.
}

static void initializeLibXMLIfNecessary()
{
    static bool didInit = false;
    if (didInit)
        return;

    // We don't want libxml to try and load catalogs.
    // FIXME: It's not nice to set global settings in libxml, embedders of Blink
    // could be trying to use libxml themselves.
    xmlCatalogSetDefaults(XML_CATA_ALLOW_NONE);
    xmlInitParser();
    xmlRegisterInputCallbacks(matchFunc, openFunc, readFunc, closeFunc);
    xmlRegisterOutputCallbacks(matchFunc, openFunc, writeFunc, closeFunc);
    libxmlLoaderThread = currentThread();
    didInit = true;
}


PassRefPtr<XMLParserContext> XMLParserContext::createStringParser(xmlSAXHandlerPtr handlers, void* userData)
{
    initializeLibXMLIfNecessary();
    xmlParserCtxtPtr parser = xmlCreatePushParserCtxt(handlers, 0, 0, 0, 0);
    parser->_private = userData;
    parser->replaceEntities = true;
    return adoptRef(new XMLParserContext(parser));
}

// Chunk should be encoded in UTF-8
PassRefPtr<XMLParserContext> XMLParserContext::createMemoryParser(xmlSAXHandlerPtr handlers, void* userData, const CString& chunk)
{
    initializeLibXMLIfNecessary();

    // appendFragmentSource() checks that the length doesn't overflow an int.
    xmlParserCtxtPtr parser = xmlCreateMemoryParserCtxt(chunk.data(), chunk.length());

    if (!parser)
        return nullptr;

    // Copy the sax handler
    memcpy(parser->sax, handlers, sizeof(xmlSAXHandler));

    // Set parser options.
    // XML_PARSE_NODICT: default dictionary option.
    // XML_PARSE_NOENT: force entities substitutions.
    xmlCtxtUseOptions(parser, XML_PARSE_NODICT | XML_PARSE_NOENT);

    // Internal initialization
    parser->sax2 = 1;
    parser->instate = XML_PARSER_CONTENT; // We are parsing a CONTENT
    parser->depth = 0;
    parser->str_xml = xmlDictLookup(parser->dict, BAD_CAST "xml", 3);
    parser->str_xmlns = xmlDictLookup(parser->dict, BAD_CAST "xmlns", 5);
    parser->str_xml_ns = xmlDictLookup(parser->dict, XML_XML_NAMESPACE, 36);
    parser->_private = userData;

    return adoptRef(new XMLParserContext(parser));
}

// --------------------------------

bool XMLDocumentParser::supportsXMLVersion(const String& version)
{
    return version == "1.0";
}

XMLDocumentParser::XMLDocumentParser(Document* document, FrameView* frameView)
    : ScriptableDocumentParser(document)
    , m_view(frameView)
    , m_context(nullptr)
    , m_currentNode(document)
    , m_isCurrentlyParsing8BitChunk(false)
    , m_sawError(false)
    , m_sawCSS(false)
    , m_sawXSLTransform(false)
    , m_sawFirstElement(false)
    , m_isXHTMLDocument(false)
    , m_parserPaused(false)
    , m_requestingScript(false)
    , m_finishCalled(false)
    , m_xmlErrors(document)
    , m_pendingScript(0)
    , m_scriptStartPosition(TextPosition::belowRangePosition())
    , m_parsingFragment(false)
{
    // This is XML being used as a document resource.
    UseCounter::count(*document, UseCounter::XMLDocument);
}

XMLDocumentParser::XMLDocumentParser(DocumentFragment* fragment, Element* parentElement, ParserContentPolicy parserContentPolicy)
    : ScriptableDocumentParser(&fragment->document(), parserContentPolicy)
    , m_view(0)
    , m_context(nullptr)
    , m_currentNode(fragment)
    , m_isCurrentlyParsing8BitChunk(false)
    , m_sawError(false)
    , m_sawCSS(false)
    , m_sawXSLTransform(false)
    , m_sawFirstElement(false)
    , m_isXHTMLDocument(false)
    , m_parserPaused(false)
    , m_requestingScript(false)
    , m_finishCalled(false)
    , m_xmlErrors(&fragment->document())
    , m_pendingScript(0)
    , m_scriptStartPosition(TextPosition::belowRangePosition())
    , m_parsingFragment(true)
{
    fragment->ref();

    // Add namespaces based on the parent node
    Vector<Element*> elemStack;
    while (parentElement) {
        elemStack.append(parentElement);

        ContainerNode* n = parentElement->parentNode();
        if (!n || !n->isElementNode())
            break;
        parentElement = toElement(n);
    }

    if (elemStack.isEmpty())
        return;

    for (; !elemStack.isEmpty(); elemStack.removeLast()) {
        Element* element = elemStack.last();
        if (element->hasAttributes()) {
            unsigned attributeCount = element->attributeCount();
            for (unsigned i = 0; i < attributeCount; ++i) {
                const Attribute& attribute = element->attributeItem(i);
                if (attribute.localName() == xmlnsAtom)
                    m_defaultNamespaceURI = attribute.value();
                else if (attribute.prefix() == xmlnsAtom)
                    m_prefixToNamespaceMap.set(attribute.localName(), attribute.value());
            }
        }
    }

    // If the parent element is not in document tree, there may be no xmlns attribute; just default to the parent's namespace.
    if (m_defaultNamespaceURI.isNull() && !parentElement->inDocument())
        m_defaultNamespaceURI = parentElement->namespaceURI();
}

XMLParserContext::~XMLParserContext()
{
    if (m_context->myDoc)
        xmlFreeDoc(m_context->myDoc);
    xmlFreeParserCtxt(m_context);
}

XMLDocumentParser::~XMLDocumentParser()
{
    // The XMLDocumentParser will always be detached before being destroyed.
    ASSERT(m_currentNodeStack.isEmpty());
    ASSERT(!m_currentNode);

    // FIXME: m_pendingScript handling should be moved into XMLDocumentParser.cpp!
    if (m_pendingScript)
        m_pendingScript->removeClient(this);
}

void XMLDocumentParser::doWrite(const String& parseString)
{
    ASSERT(!isDetached());
    if (!m_context)
        initializeParserContext();

    // Protect the libxml context from deletion during a callback
    RefPtr<XMLParserContext> context = m_context;

    // libXML throws an error if you try to switch the encoding for an empty string.
    if (parseString.length()) {
        // JavaScript may cause the parser to detach during parseChunk
        // keep this alive until this function is done.
        RefPtr<XMLDocumentParser> protect(this);

        XMLDocumentParserScope scope(document()->fetcher());
        TemporaryChange<bool> encodingScope(m_isCurrentlyParsing8BitChunk, parseString.is8Bit());
        parseChunk(context->context(), parseString);

        // JavaScript (which may be run under the parseChunk callstack) may
        // cause the parser to be stopped or detached.
        if (isStopped())
            return;
    }

    // FIXME: Why is this here?  And why is it after we process the passed source?
    if (document()->sawDecodingError()) {
        // If the decoder saw an error, report it as fatal (stops parsing)
        TextPosition position(OrdinalNumber::fromOneBasedInt(context->context()->input->line), OrdinalNumber::fromOneBasedInt(context->context()->input->col));
        handleError(XMLErrors::fatal, "Encoding error", position);
    }
}

struct _xmlSAX2Namespace {
    const xmlChar* prefix;
    const xmlChar* uri;
};
typedef struct _xmlSAX2Namespace xmlSAX2Namespace;

static inline void handleNamespaceAttributes(Vector<Attribute>& prefixedAttributes, const xmlChar** libxmlNamespaces, int nbNamespaces, ExceptionState& exceptionState)
{
    xmlSAX2Namespace* namespaces = reinterpret_cast<xmlSAX2Namespace*>(libxmlNamespaces);
    for (int i = 0; i < nbNamespaces; i++) {
        AtomicString namespaceQName = xmlnsAtom;
        AtomicString namespaceURI = toAtomicString(namespaces[i].uri);
        if (namespaces[i].prefix)
            namespaceQName = "xmlns:" + toString(namespaces[i].prefix);

        QualifiedName parsedName = anyName;
        if (!Element::parseAttributeName(parsedName, XMLNSNames::xmlnsNamespaceURI, namespaceQName, exceptionState))
            return;

        prefixedAttributes.append(Attribute(parsedName, namespaceURI));
    }
}

struct _xmlSAX2Attributes {
    const xmlChar* localname;
    const xmlChar* prefix;
    const xmlChar* uri;
    const xmlChar* value;
    const xmlChar* end;
};
typedef struct _xmlSAX2Attributes xmlSAX2Attributes;

static inline void handleElementAttributes(Vector<Attribute>& prefixedAttributes, const xmlChar** libxmlAttributes, int nbAttributes, ExceptionState& exceptionState)
{
    xmlSAX2Attributes* attributes = reinterpret_cast<xmlSAX2Attributes*>(libxmlAttributes);
    for (int i = 0; i < nbAttributes; i++) {
        int valueLength = static_cast<int>(attributes[i].end - attributes[i].value);
        AtomicString attrValue = toAtomicString(attributes[i].value, valueLength);
        String attrPrefix = toString(attributes[i].prefix);
        AtomicString attrURI = attrPrefix.isEmpty() ? AtomicString() : toAtomicString(attributes[i].uri);
        AtomicString attrQName = attrPrefix.isEmpty() ? toAtomicString(attributes[i].localname) : attrPrefix + ":" + toString(attributes[i].localname);

        QualifiedName parsedName = anyName;
        if (!Element::parseAttributeName(parsedName, attrURI, attrQName, exceptionState))
            return;

        prefixedAttributes.append(Attribute(parsedName, attrValue));
    }
}

void XMLDocumentParser::startElementNs(const AtomicString& localName, const AtomicString& prefix, const AtomicString& uri, int nbNamespaces,
    const xmlChar** libxmlNamespaces, int nbAttributes, int nbDefaulted, const xmlChar** libxmlAttributes)
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingStartElementNSCallback(localName, prefix, uri, nbNamespaces, libxmlNamespaces,
            nbAttributes, nbDefaulted, libxmlAttributes)));
        return;
    }

    exitText();

    AtomicString adjustedURI = uri;
    if (m_parsingFragment && adjustedURI.isNull()) {
        if (!prefix.isNull())
            adjustedURI = m_prefixToNamespaceMap.get(prefix);
        else
            adjustedURI = m_defaultNamespaceURI;
    }

    bool isFirstElement = !m_sawFirstElement;
    m_sawFirstElement = true;

    QualifiedName qName(prefix, localName, adjustedURI);
    RefPtr<Element> newElement = m_currentNode->document().createElement(qName, true);
    if (!newElement) {
        stopParsing();
        return;
    }

    Vector<Attribute> prefixedAttributes;
    TrackExceptionState exceptionState;
    handleNamespaceAttributes(prefixedAttributes, libxmlNamespaces, nbNamespaces, exceptionState);
    if (exceptionState.hadException()) {
        setAttributes(newElement.get(), prefixedAttributes, parserContentPolicy());
        stopParsing();
        return;
    }

    handleElementAttributes(prefixedAttributes, libxmlAttributes, nbAttributes, exceptionState);
    setAttributes(newElement.get(), prefixedAttributes, parserContentPolicy());
    if (exceptionState.hadException()) {
        stopParsing();
        return;
    }

    newElement->beginParsingChildren();

    ScriptLoader* scriptLoader = toScriptLoaderIfPossible(newElement.get());
    if (scriptLoader)
        m_scriptStartPosition = textPosition();

    m_currentNode->parserAppendChild(newElement.get());

    if (isHTMLTemplateElement(*newElement))
        pushCurrentNode(toHTMLTemplateElement(*newElement).content());
    else
        pushCurrentNode(newElement.get());

    if (isHTMLHtmlElement(*newElement))
        toHTMLHtmlElement(*newElement).insertedByParser();

    if (!m_parsingFragment && isFirstElement && document()->frame())
        document()->frame()->loader().dispatchDocumentElementAvailable();
}

void XMLDocumentParser::endElementNs()
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingEndElementNSCallback()));
        return;
    }

    // JavaScript can detach the parser.  Make sure this is not released
    // before the end of this method.
    RefPtr<XMLDocumentParser> protect(this);

    exitText();

    RefPtr<ContainerNode> n = m_currentNode;
    if (m_currentNode->isElementNode())
        toElement(n.get())->finishParsingChildren();

    if (!scriptingContentIsAllowed(parserContentPolicy()) && n->isElementNode() && toScriptLoaderIfPossible(toElement(n))) {
        popCurrentNode();
        n->remove(IGNORE_EXCEPTION);
        return;
    }

    if (!n->isElementNode() || !m_view) {
        popCurrentNode();
        return;
    }

    Element* element = toElement(n);

    // The element's parent may have already been removed from document.
    // Parsing continues in this case, but scripts aren't executed.
    if (!element->inDocument()) {
        popCurrentNode();
        return;
    }

    ScriptLoader* scriptLoader = toScriptLoaderIfPossible(element);
    if (!scriptLoader) {
        popCurrentNode();
        return;
    }

    // Don't load external scripts for standalone documents (for now).
    ASSERT(!m_pendingScript);
    m_requestingScript = true;

    if (scriptLoader->prepareScript(m_scriptStartPosition, ScriptLoader::AllowLegacyTypeInTypeAttribute)) {
        // FIXME: Script execution should be shared between
        // the libxml2 and Qt XMLDocumentParser implementations.

        if (scriptLoader->readyToBeParserExecuted()) {
            scriptLoader->executeScript(ScriptSourceCode(scriptLoader->scriptContent(), document()->url(), m_scriptStartPosition));
        } else if (scriptLoader->willBeParserExecuted()) {
            m_pendingScript = scriptLoader->resource();
            m_scriptElement = element;
            m_pendingScript->addClient(this);

            // m_pendingScript will be 0 if script was already loaded and addClient() executed it.
            if (m_pendingScript)
                pauseParsing();
        } else {
            m_scriptElement = nullptr;
        }

        // JavaScript may have detached the parser
        if (isDetached())
            return;
    }
    m_requestingScript = false;
    popCurrentNode();
}

void XMLDocumentParser::characters(const xmlChar* chars, int length)
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingCharactersCallback(chars, length)));
        return;
    }

    if (!m_leafTextNode)
        enterText();
    m_bufferedText.append(chars, length);
}

void XMLDocumentParser::error(XMLErrors::ErrorType type, const char* message, va_list args)
{
    if (isStopped())
        return;

    char formattedMessage[1024];
    vsnprintf(formattedMessage, sizeof(formattedMessage) - 1, message, args);

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingErrorCallback(type, reinterpret_cast<const xmlChar*>(formattedMessage), lineNumber(), columnNumber())));
        return;
    }

    handleError(type, formattedMessage, textPosition());
}

void XMLDocumentParser::processingInstruction(const String& target, const String& data)
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingProcessingInstructionCallback(target ,data)));
        return;
    }

    exitText();

    // ### handle exceptions
    TrackExceptionState exceptionState;
    RefPtr<ProcessingInstruction> pi = m_currentNode->document().createProcessingInstruction(target, data, exceptionState);
    if (exceptionState.hadException())
        return;

    pi->setCreatedByParser(true);

    m_currentNode->parserAppendChild(pi.get());

    pi->setCreatedByParser(false);

    if (pi->isCSS())
        m_sawCSS = true;

    if (!RuntimeEnabledFeatures::xsltEnabled())
        return;

    m_sawXSLTransform = !m_sawFirstElement && pi->isXSL();
    if (m_sawXSLTransform && !document()->transformSourceDocument()) {
        // This behavior is very tricky. We call stopParsing() here because we want to stop processing the document
        // until we're ready to apply the transform, but we actually still want to be fed decoded string pieces to
        // accumulate in m_originalSourceForTransform. So, we call stopParsing() here and
        // check isStopped() in element callbacks.
        // FIXME: This contradicts the contract of DocumentParser.
        stopParsing();
    }
}

void XMLDocumentParser::cdataBlock(const String& text)
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingCDATABlockCallback(text)));
        return;
    }

    exitText();

    RefPtr<CDATASection> newNode = CDATASection::create(m_currentNode->document(), text);
    m_currentNode->parserAppendChild(newNode.get());
}

void XMLDocumentParser::comment(const String& text)
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingCommentCallback(text)));
        return;
    }

    exitText();

    RefPtr<Comment> newNode = Comment::create(m_currentNode->document(), text);
    m_currentNode->parserAppendChild(newNode.get());
}

enum StandaloneInfo {
    StandaloneUnspecified = -2,
    NoXMlDeclaration,
    StandaloneNo,
    StandaloneYes
};

void XMLDocumentParser::startDocument(const String& version, const String& encoding, int standalone)
{
    StandaloneInfo standaloneInfo = (StandaloneInfo)standalone;
    if (standaloneInfo == NoXMlDeclaration) {
        document()->setHasXMLDeclaration(false);
        return;
    }

    if (!version.isNull())
        document()->setXMLVersion(version, ASSERT_NO_EXCEPTION);
    if (standalone != StandaloneUnspecified)
        document()->setXMLStandalone(standaloneInfo == StandaloneYes, ASSERT_NO_EXCEPTION);
    if (!encoding.isNull())
        document()->setXMLEncoding(encoding);
    document()->setHasXMLDeclaration(true);
}

void XMLDocumentParser::endDocument()
{
    exitText();
}

void XMLDocumentParser::internalSubset(const String& name, const String& externalID, const String& systemID)
{
    if (isStopped())
        return;

    if (m_parserPaused) {
        m_pendingCallbacks.append(adoptPtr(new PendingInternalSubsetCallback(name, externalID, systemID)));
        return;
    }

    if (document())
        document()->parserAppendChild(DocumentType::create(document(), name, externalID, systemID));
}

static inline XMLDocumentParser* getParser(void* closure)
{
    xmlParserCtxtPtr ctxt = static_cast<xmlParserCtxtPtr>(closure);
    return static_cast<XMLDocumentParser*>(ctxt->_private);
}

static void startElementNsHandler(void* closure, const xmlChar* localName, const xmlChar* prefix, const xmlChar* uri, int nbNamespaces, const xmlChar** namespaces, int nbAttributes, int nbDefaulted, const xmlChar** libxmlAttributes)
{
    getParser(closure)->startElementNs(toAtomicString(localName), toAtomicString(prefix), toAtomicString(uri), nbNamespaces, namespaces, nbAttributes, nbDefaulted, libxmlAttributes);
}

static void endElementNsHandler(void* closure, const xmlChar*, const xmlChar*, const xmlChar*)
{
    getParser(closure)->endElementNs();
}

static void charactersHandler(void* closure, const xmlChar* chars, int length)
{
    getParser(closure)->characters(chars, length);
}

static void processingInstructionHandler(void* closure, const xmlChar* target, const xmlChar* data)
{
    getParser(closure)->processingInstruction(toString(target), toString(data));
}

static void cdataBlockHandler(void* closure, const xmlChar* text, int length)
{
    getParser(closure)->cdataBlock(toString(text, length));
}

static void commentHandler(void* closure, const xmlChar* text)
{
    getParser(closure)->comment(toString(text));
}

WTF_ATTRIBUTE_PRINTF(2, 3)
static void warningHandler(void* closure, const char* message, ...)
{
    va_list args;
    va_start(args, message);
    getParser(closure)->error(XMLErrors::warning, message, args);
    va_end(args);
}

WTF_ATTRIBUTE_PRINTF(2, 3)
static void fatalErrorHandler(void* closure, const char* message, ...)
{
    va_list args;
    va_start(args, message);
    getParser(closure)->error(XMLErrors::fatal, message, args);
    va_end(args);
}

WTF_ATTRIBUTE_PRINTF(2, 3)
static void normalErrorHandler(void* closure, const char* message, ...)
{
    va_list args;
    va_start(args, message);
    getParser(closure)->error(XMLErrors::nonFatal, message, args);
    va_end(args);
}

// Using a static entity and marking it XML_INTERNAL_PREDEFINED_ENTITY is
// a hack to avoid malloc/free. Using a global variable like this could cause trouble
// if libxml implementation details were to change
static xmlChar sharedXHTMLEntityResult[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};

static xmlEntityPtr sharedXHTMLEntity()
{
    static xmlEntity entity;
    if (!entity.type) {
        entity.type = XML_ENTITY_DECL;
        entity.orig = sharedXHTMLEntityResult;
        entity.content = sharedXHTMLEntityResult;
        entity.etype = XML_INTERNAL_PREDEFINED_ENTITY;
    }
    return &entity;
}

static size_t convertUTF16EntityToUTF8(const UChar* utf16Entity, size_t numberOfCodeUnits, char* target, size_t targetSize)
{
    const char* originalTarget = target;
    WTF::Unicode::ConversionResult conversionResult = WTF::Unicode::convertUTF16ToUTF8(&utf16Entity,
        utf16Entity + numberOfCodeUnits, &target, target + targetSize);
    if (conversionResult != WTF::Unicode::conversionOK)
        return 0;

    // Even though we must pass the length, libxml expects the entity string to be null terminated.
    ASSERT(target > originalTarget + 1);
    *target = '\0';
    return target - originalTarget;
}

static xmlEntityPtr getXHTMLEntity(const xmlChar* name)
{
    UChar utf16DecodedEntity[4];
    size_t numberOfCodeUnits = decodeNamedEntityToUCharArray(reinterpret_cast<const char*>(name), utf16DecodedEntity);
    if (!numberOfCodeUnits)
        return 0;

    ASSERT(numberOfCodeUnits <= 4);
    size_t entityLengthInUTF8 = convertUTF16EntityToUTF8(utf16DecodedEntity, numberOfCodeUnits,
        reinterpret_cast<char*>(sharedXHTMLEntityResult), WTF_ARRAY_LENGTH(sharedXHTMLEntityResult));
    if (!entityLengthInUTF8)
        return 0;

    xmlEntityPtr entity = sharedXHTMLEntity();
    entity->length = entityLengthInUTF8;
    entity->name = name;
    return entity;
}

static xmlEntityPtr getEntityHandler(void* closure, const xmlChar* name)
{
    xmlParserCtxtPtr ctxt = static_cast<xmlParserCtxtPtr>(closure);
    xmlEntityPtr ent = xmlGetPredefinedEntity(name);
    if (ent) {
        ent->etype = XML_INTERNAL_PREDEFINED_ENTITY;
        return ent;
    }

    ent = xmlGetDocEntity(ctxt->myDoc, name);
    if (!ent && getParser(closure)->isXHTMLDocument()) {
        ent = getXHTMLEntity(name);
        if (ent)
            ent->etype = XML_INTERNAL_GENERAL_ENTITY;
    }

    return ent;
}

static void startDocumentHandler(void* closure)
{
    xmlParserCtxt* ctxt = static_cast<xmlParserCtxt*>(closure);
    XMLDocumentParser* parser = getParser(closure);
    switchEncoding(ctxt, parser->isCurrentlyParsing8BitChunk());
    parser->startDocument(toString(ctxt->version), toString(ctxt->encoding), ctxt->standalone);
    xmlSAX2StartDocument(closure);
}

static void endDocumentHandler(void* closure)
{
    getParser(closure)->endDocument();
    xmlSAX2EndDocument(closure);
}

static void internalSubsetHandler(void* closure, const xmlChar* name, const xmlChar* externalID, const xmlChar* systemID)
{
    getParser(closure)->internalSubset(toString(name), toString(externalID), toString(systemID));
    xmlSAX2InternalSubset(closure, name, externalID, systemID);
}

static void externalSubsetHandler(void* closure, const xmlChar*, const xmlChar* externalId, const xmlChar*)
{
    String extId = toString(externalId);
    if ((extId == "-//W3C//DTD XHTML 1.0 Transitional//EN")
        || (extId == "-//W3C//DTD XHTML 1.1//EN")
        || (extId == "-//W3C//DTD XHTML 1.0 Strict//EN")
        || (extId == "-//W3C//DTD XHTML 1.0 Frameset//EN")
        || (extId == "-//W3C//DTD XHTML Basic 1.0//EN")
        || (extId == "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN")
        || (extId == "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN")
        || (extId == "-//WAPFORUM//DTD XHTML Mobile 1.0//EN")
        || (extId == "-//WAPFORUM//DTD XHTML Mobile 1.1//EN")
        || (extId == "-//WAPFORUM//DTD XHTML Mobile 1.2//EN"))
        getParser(closure)->setIsXHTMLDocument(true); // controls if we replace entities or not.
}

static void ignorableWhitespaceHandler(void*, const xmlChar*, int)
{
    // nothing to do, but we need this to work around a crasher
    // http://bugzilla.gnome.org/show_bug.cgi?id=172255
    // http://bugs.webkit.org/show_bug.cgi?id=5792
}

void XMLDocumentParser::initializeParserContext(const CString& chunk)
{
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));

    sax.error = normalErrorHandler;
    sax.fatalError = fatalErrorHandler;
    sax.characters = charactersHandler;
    sax.processingInstruction = processingInstructionHandler;
    sax.cdataBlock = cdataBlockHandler;
    sax.comment = commentHandler;
    sax.warning = warningHandler;
    sax.startElementNs = startElementNsHandler;
    sax.endElementNs = endElementNsHandler;
    sax.getEntity = getEntityHandler;
    sax.startDocument = startDocumentHandler;
    sax.endDocument = endDocumentHandler;
    sax.internalSubset = internalSubsetHandler;
    sax.externalSubset = externalSubsetHandler;
    sax.ignorableWhitespace = ignorableWhitespaceHandler;
    sax.entityDecl = xmlSAX2EntityDecl;
    sax.initialized = XML_SAX2_MAGIC;
    DocumentParser::startParsing();
    m_sawError = false;
    m_sawCSS = false;
    m_sawXSLTransform = false;
    m_sawFirstElement = false;

    XMLDocumentParserScope scope(document()->fetcher());
    if (m_parsingFragment)
        m_context = XMLParserContext::createMemoryParser(&sax, this, chunk);
    else {
        ASSERT(!chunk.data());
        m_context = XMLParserContext::createStringParser(&sax, this);
    }
}

void XMLDocumentParser::doEnd()
{
    if (!isStopped()) {
        if (m_context) {
            // Tell libxml we're done.
            {
                XMLDocumentParserScope scope(document()->fetcher());
                finishParsing(context());
            }

            m_context = nullptr;
        }
    }

    bool xmlViewerMode = !m_sawError && !m_sawCSS && !m_sawXSLTransform && hasNoStyleInformation(document());
    if (xmlViewerMode) {
        XMLTreeViewer xmlTreeViewer(document());
        xmlTreeViewer.transformDocumentToTreeView();
    } else if (m_sawXSLTransform) {
        xmlDocPtr doc = xmlDocPtrForString(document()->fetcher(), m_originalSourceForTransform.toString(), document()->url().string());
        document()->setTransformSource(adoptPtr(new TransformSource(doc)));

        document()->setParsing(false); // Make the document think it's done, so it will apply XSL stylesheets.
        document()->styleResolverChanged(RecalcStyleImmediately);

        // styleResolverChanged() call can detach the parser and null out its document.
        // In that case, we just bail out.
        if (isDetached())
            return;

        document()->setParsing(true);
        DocumentParser::stopParsing();
    }
}

xmlDocPtr xmlDocPtrForString(ResourceFetcher* fetcher, const String& source, const String& url)
{
    if (source.isEmpty())
        return 0;
    // Parse in a single chunk into an xmlDocPtr
    // FIXME: Hook up error handlers so that a failure to parse the main document results in
    // good error messages.
    XMLDocumentParserScope scope(fetcher, errorFunc, 0);
    XMLParserInput input(source);
    return xmlReadMemory(input.data(), input.size(), url.latin1().data(), input.encoding(), XSLT_PARSE_OPTIONS);
}

OrdinalNumber XMLDocumentParser::lineNumber() const
{
    return OrdinalNumber::fromOneBasedInt(context() ? context()->input->line : 1);
}

OrdinalNumber XMLDocumentParser::columnNumber() const
{
    return OrdinalNumber::fromOneBasedInt(context() ? context()->input->col : 1);
}

TextPosition XMLDocumentParser::textPosition() const
{
    xmlParserCtxtPtr context = this->context();
    if (!context)
        return TextPosition::minimumPosition();
    return TextPosition(OrdinalNumber::fromOneBasedInt(context->input->line),
                        OrdinalNumber::fromOneBasedInt(context->input->col));
}

void XMLDocumentParser::stopParsing()
{
    DocumentParser::stopParsing();
    if (context())
        xmlStopParser(context());
}

void XMLDocumentParser::resumeParsing()
{
    ASSERT(!isDetached());
    ASSERT(m_parserPaused);

    m_parserPaused = false;

    // First, execute any pending callbacks
    while (!m_pendingCallbacks.isEmpty()) {
        OwnPtr<PendingCallback> callback = m_pendingCallbacks.takeFirst();
        callback->call(this);

        // A callback paused the parser
        if (m_parserPaused)
            return;
    }

    // Then, write any pending data
    SegmentedString rest = m_pendingSrc;
    m_pendingSrc.clear();
    // There is normally only one string left, so toString() shouldn't copy.
    // In any case, the XML parser runs on the main thread and it's OK if
    // the passed string has more than one reference.
    append(rest.toString().impl());

    // Finally, if finish() has been called and write() didn't result
    // in any further callbacks being queued, call end()
    if (m_finishCalled && m_pendingCallbacks.isEmpty())
        end();
}

bool XMLDocumentParser::appendFragmentSource(const String& chunk)
{
    ASSERT(!m_context);
    ASSERT(m_parsingFragment);

    CString chunkAsUtf8 = chunk.utf8();

    // libxml2 takes an int for a length, and therefore can't handle XML chunks larger than 2 GiB.
    if (chunkAsUtf8.length() > INT_MAX)
        return false;

    initializeParserContext(chunkAsUtf8);
    xmlParseContent(context());
    endDocument(); // Close any open text nodes.

    // FIXME: If this code is actually needed, it should probably move to finish()
    // XMLDocumentParserQt has a similar check (m_stream.error() == QXmlStreamReader::PrematureEndOfDocumentError) in doEnd().
    // Check if all the chunk has been processed.
    long bytesProcessed = xmlByteConsumed(context());
    if (bytesProcessed == -1 || ((unsigned long)bytesProcessed) != chunkAsUtf8.length()) {
        // FIXME: I don't believe we can hit this case without also having seen an error or a null byte.
        // If we hit this ASSERT, we've found a test case which demonstrates the need for this code.
        ASSERT(m_sawError || (bytesProcessed >= 0 && !chunkAsUtf8.data()[bytesProcessed]));
        return false;
    }

    // No error if the chunk is well formed or it is not but we have no error.
    return context()->wellFormed || !xmlCtxtGetLastError(context());
}

// --------------------------------

struct AttributeParseState {
    HashMap<String, String> attributes;
    bool gotAttributes;
};

static void attributesStartElementNsHandler(void* closure, const xmlChar* xmlLocalName, const xmlChar* /*xmlPrefix*/,
    const xmlChar* /*xmlURI*/, int /*nbNamespaces*/, const xmlChar** /*namespaces*/,
    int nbAttributes, int /*nbDefaulted*/, const xmlChar** libxmlAttributes)
{
    if (strcmp(reinterpret_cast<const char*>(xmlLocalName), "attrs") != 0)
        return;

    xmlParserCtxtPtr ctxt = static_cast<xmlParserCtxtPtr>(closure);
    AttributeParseState* state = static_cast<AttributeParseState*>(ctxt->_private);

    state->gotAttributes = true;

    xmlSAX2Attributes* attributes = reinterpret_cast<xmlSAX2Attributes*>(libxmlAttributes);
    for (int i = 0; i < nbAttributes; i++) {
        String attrLocalName = toString(attributes[i].localname);
        int valueLength = (int) (attributes[i].end - attributes[i].value);
        String attrValue = toString(attributes[i].value, valueLength);
        String attrPrefix = toString(attributes[i].prefix);
        String attrQName = attrPrefix.isEmpty() ? attrLocalName : attrPrefix + ":" + attrLocalName;

        state->attributes.set(attrQName, attrValue);
    }
}

HashMap<String, String> parseAttributes(const String& string, bool& attrsOK)
{
    AttributeParseState state;
    state.gotAttributes = false;

    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElementNs = attributesStartElementNsHandler;
    sax.initialized = XML_SAX2_MAGIC;
    RefPtr<XMLParserContext> parser = XMLParserContext::createStringParser(&sax, &state);
    String parseString = "<?xml version=\"1.0\"?><attrs " + string + " />";
    parseChunk(parser->context(), parseString);
    finishParsing(parser->context());
    attrsOK = state.gotAttributes;
    return state.attributes;
}

} // namespace WebCore
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root/Source/core/xml/parser/XMLDocumentParser.cpp

DEFINITIONS
