WebCore/dom/XMLTokenizer.cpp

/**
 * This file is part of the DOM implementation for KDE.
 *
 * Copyright (C) 2000 Peter Kelly (pmk@post.com)
 * Copyright (C) 2005, 2006 Apple Computer, Inc.
 * Copyright (C) 2006 Alexey Proskuryakov
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include "config.h"
#include "XMLTokenizer.h"

#include "CDATASection.h"
#include "CString.h"
#include "Cache.h"
#include "CachedScript.h"
#include "Comment.h"
#include "DocLoader.h"
#include "Document.h"
#include "DocumentFragment.h"
#include "DocumentType.h"
#include "EventNames.h"
#include "Frame.h"
#include "HTMLNames.h"
#include "HTMLScriptElement.h"
#include "HTMLTableSectionElement.h"
#include "HTMLTokenizer.h"
#include "LoaderFunctions.h"
#include "ProcessingInstruction.h"
#include "ResourceLoader.h"
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <wtf/Platform.h>
#include <wtf/Vector.h>

#ifdef XSLT_SUPPORT
#include <libxslt/xslt.h>
#endif

#ifdef SVG_SUPPORT
#include "SVGNames.h"
#include "XLinkNames.h"
#endif

using namespace std;

namespace WebCore {

using namespace EventNames;
using namespace HTMLNames;

const int maxErrors = 25;

typedef HashMap<StringImpl*, StringImpl*> PrefixForNamespaceMap;

class PendingCallbacks;

class XMLTokenizer : public Tokenizer, public CachedResourceClient {
public:
    XMLTokenizer(Document *, FrameView * = 0);
    XMLTokenizer(DocumentFragment *, Element *);
    ~XMLTokenizer();

    enum ErrorType { warning, nonFatal, fatal };

    // from Tokenizer
    virtual bool write(const SegmentedString &str, bool);
    virtual void finish();
    virtual bool isWaitingForScripts() const;
    virtual void stopParsing();

    void end();

    void pauseParsing();
    void resumeParsing();
    
    void setIsXHTMLDocument(bool isXHTML) { m_isXHTMLDocument = isXHTML; }
    bool isXHTMLDocument() const { return m_isXHTMLDocument; }

    // from CachedResourceClient
    virtual void notifyFinished(CachedResource *finishedObj);

    // callbacks from parser SAX
    void error(ErrorType, const char *message, va_list args);
    void startElementNs(const xmlChar *xmlLocalName, const xmlChar *xmlPrefix, const xmlChar *xmlURI, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, const xmlChar **libxmlAttributes);
    void endElementNs();
    void characters(const xmlChar *s, int len);
    void processingInstruction(const xmlChar *target, const xmlChar *data);
    void cdataBlock(const xmlChar *s, int len);
    void comment(const xmlChar *s);
    void internalSubset(const xmlChar *name, const xmlChar *externalID, const xmlChar *systemID);

    void handleError(ErrorType type, const char* m, int lineNumber, int columnNumber);
    
private:
    void initializeParserContext();
    void setCurrentNode(Node*);

    int lineNumber() const;
    int columnNumber() const;

    void insertErrorMessageBlock();

    bool enterText();
    void exitText();

    Document *m_doc;
    FrameView *m_view;
    
    String m_originalSourceForTransform;

    xmlParserCtxtPtr m_context;
    Node *m_currentNode;
    bool m_currentNodeIsReferenced;

    bool m_sawError;
    bool m_sawXSLTransform;
    bool m_sawFirstElement;
    bool m_isXHTMLDocument;
    
    bool m_parserPaused;
    bool m_requestingScript;
    bool m_finishCalled;
    
    int m_errorCount;
    int m_lastErrorLine;
    int m_lastErrorColumn;
    String m_errorMessages;

    CachedScript *m_pendingScript;
    RefPtr<Element> m_scriptElement;
    int m_scriptStartLine;
    
    bool m_parsingFragment;
    String m_defaultNamespaceURI;
    PrefixForNamespaceMap m_prefixToNamespaceMap;
    
    PendingCallbacks* m_pendingCallbacks;
    SegmentedString m_pendingSrc;
};

class PendingCallbacks {
public:
    PendingCallbacks()
    {
        m_callbacks.setAutoDelete(true);
    }
    
    void appendStartElementNSCallback(const xmlChar *xmlLocalName, const xmlChar *xmlPrefix, const xmlChar *xmlURI, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, const xmlChar **attributes)
    {
        PendingStartElementNSCallback* callback = new PendingStartElementNSCallback;
        
        callback->xmlLocalName = xmlStrdup(xmlLocalName);
        callback->xmlPrefix = xmlStrdup(xmlPrefix);
        callback->xmlURI = xmlStrdup(xmlURI);
        callback->nb_namespaces = nb_namespaces;
        callback->namespaces = reinterpret_cast<xmlChar**>(xmlMalloc(sizeof (xmlChar*) * nb_namespaces * 2));
        for (int i = 0; i < nb_namespaces * 2 ; i++)
            callback->namespaces[i] = xmlStrdup(namespaces[i]);
        callback->nb_attributes = nb_attributes;
        callback->nb_defaulted = nb_defaulted;
        callback->attributes =  reinterpret_cast<xmlChar**>(xmlMalloc(sizeof (xmlChar*) * nb_attributes * 5));
        for (int i = 0; i < nb_attributes; i++) {
            // Each attribute has 5 elements in the array:
            // name, prefix, uri, value and an end pointer.
            
            for (int j = 0; j < 3; j++)
                callback->attributes[i * 5 + j] = xmlStrdup(attributes[i * 5 + j]);
            
            int len = attributes[i * 5 + 4] - attributes[i * 5 + 3];

            callback->attributes[i * 5 + 3] = xmlStrndup(attributes[i * 5 + 3], len);
            callback->attributes[i * 5 + 4] = callback->attributes[i * 5 + 3] + len;
        }
        
        m_callbacks.append(callback);
    }

    void appendEndElementNSCallback()
    {
        PendingEndElementNSCallback* callback = new PendingEndElementNSCallback;
        
        m_callbacks.append(callback);
    }
    
    void appendCharactersCallback(const xmlChar *s, int len)
    {
        PendingCharactersCallback* callback = new PendingCharactersCallback;
        
        callback->s = xmlStrndup(s, len);
        callback->len = len;
        
        m_callbacks.append(callback);        
    }
    
    void appendProcessingInstructionCallback(const xmlChar *target, const xmlChar *data)
    {
        PendingProcessingInstructionCallback* callback = new PendingProcessingInstructionCallback;
        
        callback->target = xmlStrdup(target);
        callback->data = xmlStrdup(data);
        
        m_callbacks.append(callback);
    }
    
    void appendCDATABlockCallback(const xmlChar *s, int len)
    {
        PendingCDATABlockCallback* callback = new PendingCDATABlockCallback;
        
        callback->s = xmlStrndup(s, len);
        callback->len = len;
        
        m_callbacks.append(callback);        
    }

    void appendCommentCallback(const xmlChar *s)
    {
        PendingCommentCallback* callback = new PendingCommentCallback;
        
        callback->s = xmlStrdup(s);
        
        m_callbacks.append(callback);        
    }

    void appendInternalSubsetCallback(const xmlChar *name, const xmlChar *externalID, const xmlChar *systemID)
    {
        PendingInternalSubsetCallback* callback = new PendingInternalSubsetCallback;
        
        callback->name = xmlStrdup(name);
        callback->externalID = xmlStrdup(externalID);
        callback->systemID = xmlStrdup(systemID);
        
        m_callbacks.append(callback);        
    }
    
    void appendErrorCallback(XMLTokenizer::ErrorType type, const char* message, int lineNumber, int columnNumber)
    {
        PendingErrorCallback* callback = new PendingErrorCallback;
        
        callback->message = strdup(message);
        callback->type = type;
        callback->lineNumber = lineNumber;
        callback->columnNumber = columnNumber;
        
        m_callbacks.append(callback);
    }

    void callAndRemoveFirstCallback(XMLTokenizer* tokenizer)
    {
        PendingCallback *cb = m_callbacks.getFirst();
            
        cb->call(tokenizer);
        m_callbacks.removeFirst();
    }
    
    bool isEmpty() const { return m_callbacks.isEmpty(); }
    
private:    
    struct PendingCallback {        
        
        virtual ~PendingCallback() { } 

        virtual void call(XMLTokenizer* tokenizer) = 0;
    };  
    
    struct PendingStartElementNSCallback : public PendingCallback {        
        virtual ~PendingStartElementNSCallback() {
            xmlFree(xmlLocalName);
            xmlFree(xmlPrefix);
            xmlFree(xmlURI);
            for (int i = 0; i < nb_namespaces * 2; i++)
                xmlFree(namespaces[i]);
            xmlFree(namespaces);
            for (int i = 0; i < nb_attributes; i++)
                for (int j = 0; j < 4; j++) 
                    xmlFree(attributes[i * 5 + j]);
            xmlFree(attributes);
        }
        
        virtual void call(XMLTokenizer* tokenizer) {
            tokenizer->startElementNs(xmlLocalName, xmlPrefix, xmlURI, 
                                      nb_namespaces, (const xmlChar**)namespaces,
                                      nb_attributes, nb_defaulted, (const xmlChar**)(attributes));
        }

        xmlChar* xmlLocalName;
        xmlChar* xmlPrefix;
        xmlChar* xmlURI;
        int nb_namespaces;
        xmlChar** namespaces;
        int nb_attributes;
        int nb_defaulted;
        xmlChar** attributes;
    };
    
    struct PendingEndElementNSCallback : public PendingCallback {
        virtual void call(XMLTokenizer* tokenizer) 
        {
            tokenizer->endElementNs();
        }
    };
    
    struct PendingCharactersCallback : public PendingCallback {
        virtual ~PendingCharactersCallback() 
        {
            xmlFree(s);
        }
    
        virtual void call(XMLTokenizer* tokenizer) 
        {
            tokenizer->characters(s, len);
        }
        
        xmlChar* s;
        int len;
    };

    struct PendingProcessingInstructionCallback : public PendingCallback {
        virtual ~PendingProcessingInstructionCallback() 
        {
            xmlFree(target);
            xmlFree(data);
        }
        
        virtual void call(XMLTokenizer* tokenizer) 
        {
            tokenizer->processingInstruction(target, data);
        }
        
        xmlChar* target;
        xmlChar* data;
    };
    
    struct PendingCDATABlockCallback : public PendingCallback {
        virtual ~PendingCDATABlockCallback() 
        {
            xmlFree(s);
        }
        
        virtual void call(XMLTokenizer* tokenizer) 
        {
            tokenizer->cdataBlock(s, len);
        }
        
        xmlChar* s;
        int len;
    };

    struct PendingCommentCallback : public PendingCallback {
        virtual ~PendingCommentCallback() 
        {
            xmlFree(s);
        }
        
        virtual void call(XMLTokenizer* tokenizer) 
        {
            tokenizer->comment(s);
        }

        xmlChar* s;
    };
    
    struct PendingInternalSubsetCallback : public PendingCallback {
        virtual ~PendingInternalSubsetCallback() 
        {
            xmlFree(name);
            xmlFree(externalID);
            xmlFree(systemID);
        }
        
        virtual void call(XMLTokenizer* tokenizer)
        {
            tokenizer->internalSubset(name, externalID, systemID);
        }
        
        xmlChar* name;
        xmlChar* externalID;
        xmlChar* systemID;        
    };
    
    struct PendingErrorCallback: public PendingCallback {
        virtual ~PendingErrorCallback() 
        {
            free (message);
        }
        
        virtual void call(XMLTokenizer* tokenizer) 
        {
            tokenizer->handleError(type, message, lineNumber, columnNumber);
        }
        
        XMLTokenizer::ErrorType type;
        char* message;
        int lineNumber;
        int columnNumber;
    };
    
public:
    DeprecatedPtrList<PendingCallback> m_callbacks;
};

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

static int globalDescriptor = 0;

static int matchFunc(const char* uri)
{
    return 1; // Match everything.
}

static DocLoader *globalDocLoader = 0;

class OffsetBuffer {
public:
    OffsetBuffer(const Vector<char>& b) : m_buffer(b), m_currentOffset(0) { }
    
    int readOutBytes(char *outputBuffer, unsigned askedToRead) {
        unsigned bytesLeft = m_buffer.size() - m_currentOffset;
        unsigned lenToCopy = min(askedToRead, bytesLeft);
        if (lenToCopy) {
            memcpy(outputBuffer, m_buffer.data() + m_currentOffset, lenToCopy);
            m_currentOffset += lenToCopy;
        }
        return lenToCopy;
    }

private:
    Vector<char> m_buffer;
    unsigned m_currentOffset;
};

static bool shouldAllowExternalLoad(const char* inURI)
{
    if (strstr(inURI, "/etc/xml/catalog")
            || strstr(inURI, "http://www.w3.org/Graphics/SVG") == inURI
            || strstr(inURI, "http://www.w3.org/TR/xhtml") == inURI)
        return false;
    return true;
}

static void* openFunc(const char* uri)
{
    if (!globalDocLoader || !shouldAllowExternalLoad(uri))
        return &globalDescriptor;

    KURL finalURL;
    RefPtr<ResourceLoader> loader = ResourceLoader::create(0, "GET", uri);
    DeprecatedString headers;
    Vector<char> data = ServeSynchronousRequest(Cache::loader(), globalDocLoader, loader.get(), finalURL, headers);
    
    return new OffsetBuffer(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;
        
    OffsetBuffer *data = static_cast<OffsetBuffer *>(context);
    return data->readOutBytes(buffer, len);
}

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

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

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

void setLoaderForLibXMLCallbacks(DocLoader *docLoader)
{
    globalDocLoader = docLoader;
}

static xmlParserCtxtPtr createStringParser(xmlSAXHandlerPtr handlers, void* userData)
{
    static bool didInit = false;
    if (!didInit) {
        xmlInitParser();
        xmlRegisterInputCallbacks(matchFunc, openFunc, readFunc, closeFunc);
        xmlRegisterOutputCallbacks(matchFunc, openFunc, writeFunc, closeFunc);
        didInit = true;
    }

    xmlParserCtxtPtr parser = xmlCreatePushParserCtxt(handlers, 0, 0, 0, 0);
    parser->_private = userData;
    parser->replaceEntities = true;
    const UChar BOM = 0xFEFF;
    const unsigned char BOMHighByte = *reinterpret_cast<const unsigned char*>(&BOM);
    xmlSwitchEncoding(parser, BOMHighByte == 0xFF ? XML_CHAR_ENCODING_UTF16LE : XML_CHAR_ENCODING_UTF16BE);
    return parser;
}

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

XMLTokenizer::XMLTokenizer(Document *_doc, FrameView *_view)
    : m_doc(_doc)
    , m_view(_view)
    , m_context(0)
    , m_currentNode(_doc)
    , m_currentNodeIsReferenced(false)
    , m_sawError(false)
    , m_sawXSLTransform(false)
    , m_sawFirstElement(false)
    , m_isXHTMLDocument(false)
    , m_parserPaused(false)
    , m_requestingScript(false)
    , m_finishCalled(false)
    , m_errorCount(0)
    , m_lastErrorLine(0)
    , m_lastErrorColumn(0)
    , m_pendingScript(0)
    , m_scriptStartLine(0)
    , m_parsingFragment(false)
    , m_pendingCallbacks(new PendingCallbacks)
{
}

XMLTokenizer::XMLTokenizer(DocumentFragment *fragment, Element *parentElement)
    : m_doc(fragment->document())
    , m_view(0)
    , m_context(0)
    , m_currentNode(fragment)
    , m_currentNodeIsReferenced(fragment)
    , m_sawError(false)
    , m_sawXSLTransform(false)
    , m_sawFirstElement(false)
    , m_isXHTMLDocument(false)
    , m_parserPaused(false)
    , m_requestingScript(false)
    , m_finishCalled(false)
    , m_errorCount(0)
    , m_lastErrorLine(0)
    , m_lastErrorColumn(0)
    , m_pendingScript(0)
    , m_scriptStartLine(0)
    , m_parsingFragment(true)
    , m_pendingCallbacks(new PendingCallbacks)
{
    if (fragment)
        fragment->ref();
    if (m_doc)
        m_doc->ref();
          
    // Add namespaces based on the parent node
    Vector<Element*> elemStack;
    while (parentElement) {
        elemStack.append(parentElement);
        
        Node *n = parentElement->parentNode();
        if (!n || !n->isElementNode())
            break;
        parentElement = static_cast<Element *>(n);
    }
    
    if (elemStack.isEmpty())
        return;
    
    for (Element *element = elemStack.last(); !elemStack.isEmpty(); elemStack.removeLast()) {
        if (NamedAttrMap *attrs = element->attributes()) {
            for (unsigned i = 0; i < attrs->length(); i++) {
                Attribute *attr = attrs->attributeItem(i);
                if (attr->localName() == "xmlns")
                    m_defaultNamespaceURI = attr->value();
                else if (attr->prefix() == "xmlns")
                    m_prefixToNamespaceMap.set(attr->localName().impl(), attr->value().impl());
            }
        }
    }
}

XMLTokenizer::~XMLTokenizer()
{
    setCurrentNode(0);
    if (m_parsingFragment && m_doc)
        m_doc->deref();
    delete m_pendingCallbacks;
    if (m_pendingScript)
        m_pendingScript->deref(this);
}

void XMLTokenizer::setCurrentNode(Node* n)
{
    bool nodeNeedsReference = n && n != m_doc;
    if (nodeNeedsReference)
        n->ref(); 
    if (m_currentNodeIsReferenced) 
        m_currentNode->deref(); 
    m_currentNode = n;
    m_currentNodeIsReferenced = nodeNeedsReference;
}

bool XMLTokenizer::write(const SegmentedString& s, bool /*appendData*/)
{
    String parseString = s.toString();
    
    if (m_sawXSLTransform || !m_sawFirstElement)
        m_originalSourceForTransform += parseString;

    if (m_parserStopped || m_sawXSLTransform)
        return false;
    
    if (m_parserPaused) {
        m_pendingSrc.append(s);
        return false;
    }
    
    if (!m_context)
        initializeParserContext();
    
    // libXML throws an error if you try to switch the encoding for an empty string.
    if (parseString.length()) {
        // 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.
        const UChar BOM = 0xFEFF;
        const unsigned char BOMHighByte = *reinterpret_cast<const unsigned char*>(&BOM);
        xmlSwitchEncoding(m_context, BOMHighByte == 0xFF ? XML_CHAR_ENCODING_UTF16LE : XML_CHAR_ENCODING_UTF16BE);

        xmlParseChunk(m_context, reinterpret_cast<const char*>(parseString.characters()), sizeof(UChar) * parseString.length(), 0);
    }
    
    return false;
}

inline String toString(const xmlChar* str, unsigned len)
{
    return UTF8Encoding().decode(reinterpret_cast<const char*>(str), len);
}

inline String toString(const xmlChar* str)
{
    const char* cstr = str ? reinterpret_cast<const char*>(str) : "";
    return UTF8Encoding().decode(cstr, strlen(cstr));
}

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

static inline void handleElementNamespaces(Element *newElement, const xmlChar **libxmlNamespaces, int nb_namespaces, ExceptionCode& ec)
{
    xmlSAX2Namespace *namespaces = reinterpret_cast<xmlSAX2Namespace *>(libxmlNamespaces);
    for(int i = 0; i < nb_namespaces; i++) {
        String namespaceQName = "xmlns";
        String namespaceURI = toString(namespaces[i].uri);
        if (namespaces[i].prefix)
            namespaceQName = "xmlns:" + toString(namespaces[i].prefix);
        newElement->setAttributeNS("http://www.w3.org/2000/xmlns/", namespaceQName, namespaceURI, ec);
        if (ec) // exception setting attributes
            return;
    }
}

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(Element *newElement, const xmlChar **libxmlAttributes, int nb_attributes, ExceptionCode& ec)
{
    xmlSAX2Attributes *attributes = reinterpret_cast<xmlSAX2Attributes *>(libxmlAttributes);
    for(int i = 0; i < nb_attributes; 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 attrURI = attrPrefix.isEmpty() ? String() : toString(attributes[i].uri);
        String attrQName = attrPrefix.isEmpty() ? attrLocalName : attrPrefix + ":" + attrLocalName;
        
        newElement->setAttributeNS(attrURI, attrQName, attrValue, ec);
        if (ec) // exception setting attributes
            return;
    }
}

void XMLTokenizer::startElementNs(const xmlChar *xmlLocalName, const xmlChar *xmlPrefix, const xmlChar *xmlURI, int nb_namespaces, const xmlChar **libxmlNamespaces, int nb_attributes, int nb_defaulted, const xmlChar **libxmlAttributes)
{
    if (m_parserStopped)
        return;
    
    if (m_parserPaused) {        
        m_pendingCallbacks->appendStartElementNSCallback(xmlLocalName, xmlPrefix, xmlURI, nb_namespaces, libxmlNamespaces, nb_attributes, nb_defaulted, libxmlAttributes);
        return;
    }
    
    m_sawFirstElement = true;

    exitText();

    String localName = toString(xmlLocalName);
    String uri = toString(xmlURI);
    String prefix = toString(xmlPrefix);
    String qName = prefix.isEmpty() ? localName : prefix + ":" + localName;
    
    if (m_parsingFragment && uri.isEmpty()) {
        if (!prefix.isEmpty())
            uri = String(m_prefixToNamespaceMap.get(prefix.impl()));
        else
            uri = m_defaultNamespaceURI;
    }

    ExceptionCode ec = 0;
    RefPtr<Element> newElement = m_doc->createElementNS(uri, qName, ec);
    if (!newElement) {
        stopParsing();
        return;
    }
    
    handleElementNamespaces(newElement.get(), libxmlNamespaces, nb_namespaces, ec);
    if (ec) {
        stopParsing();
        return;
    }
    
    handleElementAttributes(newElement.get(), libxmlAttributes, nb_attributes, ec);
    if (ec) {
        stopParsing();
        return;
    }

    // FIXME: This hack ensures implicit table bodies get constructed in XHTML and XML files.
    // We want to consolidate this with the HTML parser and HTML DOM code at some point.
    // For now, it's too risky to rip that code up.
    if (m_currentNode->hasTagName(tableTag) && newElement->hasTagName(trTag)) {
        RefPtr<Node> implicitTBody = new HTMLTableSectionElement(tbodyTag, m_doc, true /* implicit */);
        m_currentNode->addChild(implicitTBody.get());
        setCurrentNode(implicitTBody.get());
        if (m_view && !implicitTBody->attached())
            implicitTBody->attach();
    }

    if (newElement->hasTagName(scriptTag))
        static_cast<HTMLScriptElement *>(newElement.get())->setCreatedByParser(true);
    
    if (newElement->hasTagName(HTMLNames::scriptTag)
#ifdef SVG_SUPPORT
        || newElement->hasTagName(SVGNames::scriptTag)
#endif
        )
        m_scriptStartLine = lineNumber();
    
    if (!m_currentNode->addChild(newElement.get())) {
        stopParsing();
        return;
    }
    
    setCurrentNode(newElement.get());
    if (m_view && !newElement->attached())
        newElement->attach();
}

void XMLTokenizer::endElementNs()
{
    if (m_parserStopped)
        return;

    if (m_parserPaused) {
        m_pendingCallbacks->appendEndElementNSCallback();
        return;
    }
    
    exitText();

    Node *n = m_currentNode;
    while (n->implicitNode())
        n = n->parentNode();
    RefPtr<Node> parent = n->parentNode();
    n->closeRenderer();
    
    // don't load external scripts for standalone documents (for now)
    if (n->isElementNode() && m_view && (static_cast<Element*>(n)->hasTagName(scriptTag) 
#ifdef SVG_SUPPORT
                                         || static_cast<Element*>(n)->hasTagName(SVGNames::scriptTag)
#endif
                                         )) {

                                         
        ASSERT(!m_pendingScript);
        
        m_requestingScript = true;
        
        Element* scriptElement = static_cast<Element*>(n);        
        String scriptHref;
        
        if (static_cast<Element*>(n)->hasTagName(scriptTag))
            scriptHref = scriptElement->getAttribute(srcAttr);
#ifdef SVG_SUPPORT
        else if (static_cast<Element*>(n)->hasTagName(SVGNames::scriptTag))
            scriptHref = scriptElement->getAttribute(XLinkNames::hrefAttr);
#endif
        
        if (!scriptHref.isEmpty()) {
            // we have a src attribute 
            const AtomicString& charset = scriptElement->getAttribute(charsetAttr);
            if ((m_pendingScript = m_doc->docLoader()->requestScript(scriptHref, charset))) {
                m_scriptElement = scriptElement;
                m_pendingScript->ref(this);
                    
                // m_pendingScript will be 0 if script was already loaded and ref() executed it
                if (m_pendingScript)
                    pauseParsing();
            } else 
                m_scriptElement = 0;

        } else {
            String scriptCode = "";
            for (Node *child = scriptElement->firstChild(); child; child = child->nextSibling()) {
                if (child->isTextNode() || child->nodeType() == Node::CDATA_SECTION_NODE)
                    scriptCode += static_cast<CharacterData*>(child)->data();
            }
            m_view->frame()->executeScript(m_doc->URL(), m_scriptStartLine - 1, 0, scriptCode);
        }
        
        m_requestingScript = false;
    }

    setCurrentNode(parent.get());
}

void XMLTokenizer::characters(const xmlChar *s, int len)
{
    if (m_parserStopped)
        return;
    
    if (m_parserPaused) {
        m_pendingCallbacks->appendCharactersCallback(s, len);
        return;
    }
    
    if (m_currentNode->isTextNode() || enterText()) {
        ExceptionCode ec = 0;
        static_cast<Text*>(m_currentNode)->appendData(toString(s, len), ec);
    }
}

bool XMLTokenizer::enterText()
{
    RefPtr<Node> newNode = new Text(m_doc, "");
    if (!m_currentNode->addChild(newNode.get()))
        return false;
    setCurrentNode(newNode.get());
    return true;
}

void XMLTokenizer::exitText()
{
    if (m_parserStopped)
        return;

    if (!m_currentNode || !m_currentNode->isTextNode())
        return;

    if (m_view && m_currentNode && !m_currentNode->attached())
        m_currentNode->attach();

    // FIXME: What's the right thing to do if the parent is really 0?
    // Just leaving the current node set to the text node doesn't make much sense.
    if (Node* par = m_currentNode->parentNode())
        setCurrentNode(par);
}

void XMLTokenizer::handleError(ErrorType type, const char* m, int lineNumber, int columnNumber)
{
    if (type == fatal || (m_errorCount < maxErrors && m_lastErrorLine != lineNumber && m_lastErrorColumn != columnNumber)) {
        switch (type) {
            case warning:
                m_errorMessages += String::sprintf("warning on line %d at column %d: %s", lineNumber, columnNumber, m);
                break;
            case fatal:
            case nonFatal:
                m_errorMessages += String::sprintf("error on line %d at column %d: %s", lineNumber, columnNumber, m);
        }
        
        m_lastErrorLine = lineNumber;
        m_lastErrorColumn = columnNumber;
        ++m_errorCount;
    }
    
    if (type != warning)
        m_sawError = true;
    
    if (type == fatal)
        stopParsing();    
}

void XMLTokenizer::error(ErrorType type, const char *message, va_list args)
{
    if (m_parserStopped)
        return;

#if PLATFORM(WIN_OS)
    char m[1024];
    vsnprintf(m, sizeof(m) - 1, message, args);
#else
    char *m;
    vasprintf(&m, message, args);
#endif
    
    if (m_parserPaused)
        m_pendingCallbacks->appendErrorCallback(type, m, lineNumber(), columnNumber());
    else
        handleError(type, m, lineNumber(), columnNumber());

#if !PLATFORM(WIN_OS)
    free(m);
#endif
}

void XMLTokenizer::processingInstruction(const xmlChar *target, const xmlChar *data)
{
    if (m_parserStopped)
        return;

    if (m_parserPaused) {
        m_pendingCallbacks->appendProcessingInstructionCallback(target, data);
        return;
    }
    
    exitText();

    // ### handle exceptions
    int exception = 0;
    RefPtr<ProcessingInstruction> pi = m_doc->createProcessingInstruction(
        toString(target), toString(data), exception);
    if (exception)
        return;

    if (!m_currentNode->addChild(pi.get()))
        return;
    if (m_view && !pi->attached())
        pi->attach();

    // don't load stylesheets for standalone documents
    if (m_doc->frame()) {
        m_sawXSLTransform = !m_sawFirstElement && !pi->checkStyleSheet();
#ifdef XSLT_SUPPORT
        // Pretend we didn't see this PI if we're the result of a transform.
        if (m_sawXSLTransform && !m_doc->transformSourceDocument())
#else
        if (m_sawXSLTransform)
#endif
            // Stop the SAX parser.
            stopParsing();
    }
}

void XMLTokenizer::cdataBlock(const xmlChar *s, int len)
{
    if (m_parserStopped)
        return;

    if (m_parserPaused) {
        m_pendingCallbacks->appendCDATABlockCallback(s, len);
        return;
    }
    
    exitText();

    RefPtr<Node> newNode = new CDATASection(m_doc, toString(s, len));
    if (!m_currentNode->addChild(newNode.get()))
        return;
    if (m_view && !newNode->attached())
        newNode->attach();
}

void XMLTokenizer::comment(const xmlChar *s)
{
    if (m_parserStopped)
        return;

    if (m_parserPaused) {
        m_pendingCallbacks->appendCommentCallback(s);
        return;
    }
    
    exitText();

    RefPtr<Node> newNode = new Comment(m_doc, toString(s));
    m_currentNode->addChild(newNode.get());
    if (m_view && !newNode->attached())
        newNode->attach();
}

void XMLTokenizer::internalSubset(const xmlChar *name, const xmlChar *externalID, const xmlChar *systemID)
{
    if (m_parserStopped)
        return;

    if (m_parserPaused) {
        m_pendingCallbacks->appendInternalSubsetCallback(name, externalID, systemID);
        return;
    }
    
    Document *doc = m_doc;
    if (!doc)
        return;

    doc->setDocType(new DocumentType(doc, toString(name), toString(externalID), toString(systemID)));
}

inline XMLTokenizer *getTokenizer(void *closure)
{
    xmlParserCtxtPtr ctxt = static_cast<xmlParserCtxtPtr>(closure);
    return static_cast<XMLTokenizer *>(ctxt->_private);
}

// This is a hack around http://bugzilla.gnome.org/show_bug.cgi?id=159219
// Otherwise libxml seems to call all the SAX callbacks twice for any replaced entity.
static inline bool hackAroundLibXMLEntityBug(void *closure)
{
    return static_cast<xmlParserCtxtPtr>(closure)->node;
}

static void startElementNsHandler(void *closure, const xmlChar *localname, const xmlChar *prefix, const xmlChar *uri, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, const xmlChar **libxmlAttributes)
{
    if (hackAroundLibXMLEntityBug(closure))
        return;

    getTokenizer(closure)->startElementNs(localname, prefix, uri, nb_namespaces, namespaces, nb_attributes, nb_defaulted, libxmlAttributes);
}

static void endElementNsHandler(void *closure, const xmlChar *localname, const xmlChar *prefix, const xmlChar *uri)
{
    if (hackAroundLibXMLEntityBug(closure))
        return;
    
    getTokenizer(closure)->endElementNs();
}

static void charactersHandler(void *closure, const xmlChar *s, int len)
{
    if (hackAroundLibXMLEntityBug(closure))
        return;
    
    getTokenizer(closure)->characters(s, len);
}

static void processingInstructionHandler(void *closure, const xmlChar *target, const xmlChar *data)
{
    if (hackAroundLibXMLEntityBug(closure))
        return;
    
    getTokenizer(closure)->processingInstruction(target, data);
}

static void cdataBlockHandler(void *closure, const xmlChar *s, int len)
{
    if (hackAroundLibXMLEntityBug(closure))
        return;
    
    getTokenizer(closure)->cdataBlock(s, len);
}

static void commentHandler(void *closure, const xmlChar *comment)
{
    if (hackAroundLibXMLEntityBug(closure))
        return;
    
    getTokenizer(closure)->comment(comment);
}

static void warningHandler(void *closure, const char *message, ...)
{
    va_list args;
    va_start(args, message);
    getTokenizer(closure)->error(XMLTokenizer::warning, message, args);
    va_end(args);
}

static void fatalErrorHandler(void *closure, const char *message, ...)
{
    va_list args;
    va_start(args, message);
    getTokenizer(closure)->error(XMLTokenizer::fatal, message, args);
    va_end(args);
}

static void normalErrorHandler(void *closure, const char *message, ...)
{
    va_list args;
    va_start(args, message);
    getTokenizer(closure)->error(XMLTokenizer::nonFatal, message, args);
    va_end(args);
}

// Using a global variable 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[5] = {0,0,0,0,0};
static xmlEntity sharedXHTMLEntity = {
    0, XML_ENTITY_DECL, 0, 0, 0, 0, 0, 0, 0, 
    sharedXHTMLEntityResult, sharedXHTMLEntityResult, 0,
    XML_INTERNAL_PREDEFINED_ENTITY, 0, 0, 0, 0, 0
};

static xmlEntityPtr getXHTMLEntity(const xmlChar* name)
{
    UChar c = decodeNamedEntity(reinterpret_cast<const char*>(name));
    if (!c)
        return 0;

    CString value = String(&c, 1).utf8();
    assert(value.length() < 5);
    sharedXHTMLEntity.length = value.length();
    sharedXHTMLEntity.name = name;
    memcpy(sharedXHTMLEntityResult, value.data(), sharedXHTMLEntity.length + 1);

    return &sharedXHTMLEntity;
}

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

    ent = xmlGetDocEntity(ctxt->myDoc, name);
    if (!ent && getTokenizer(closure)->isXHTMLDocument())
        ent = getXHTMLEntity(name);
    
    return ent;
}

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

static void externalSubsetHandler(void *closure, const xmlChar *name, const xmlChar *externalId, const xmlChar *systemId)
{
    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"))
        getTokenizer(closure)->setIsXHTMLDocument(true); // controls if we replace entities or not.
}

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

void XMLTokenizer::initializeParserContext()
{
    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 = xmlSAX2StartDocument;
    sax.internalSubset = internalSubsetHandler;
    sax.externalSubset = externalSubsetHandler;
    sax.ignorableWhitespace = ignorableWhitespaceHandler;
    sax.entityDecl = xmlSAX2EntityDecl;
    sax.initialized = XML_SAX2_MAGIC;
    
    m_parserStopped = false;
    m_sawError = false;
    m_sawXSLTransform = false;
    m_sawFirstElement = false;
    m_context = createStringParser(&sax, this);
}

void XMLTokenizer::end()
{
    if (m_sawXSLTransform) {
        m_doc->setTransformSource(xmlDocPtrForString(m_doc->docLoader(), m_originalSourceForTransform, m_doc->URL()));
        
        m_doc->setParsing(false); // Make the doc think it's done, so it will apply xsl sheets.
        m_doc->updateStyleSelector();
        m_doc->setParsing(true);
        m_parserStopped = true;
    }
    
    if (m_context) {
        // Tell libxml we're done.
        xmlParseChunk(m_context, 0, 0, 1);
        
        if (m_context->myDoc)
            xmlFreeDoc(m_context->myDoc);
        xmlFreeParserCtxt(m_context);
        m_context = 0;
    }
    
    if (m_sawError)
        insertErrorMessageBlock();
    else {
        exitText();
        m_doc->updateStyleSelector();
    }
    
    setCurrentNode(0);
    m_doc->finishedParsing();    
}

void XMLTokenizer::finish()
{
    if (m_parserPaused)
        m_finishCalled = true;
    else
        end();
}

static inline RefPtr<Element> createXHTMLParserErrorHeader(Document* doc, const String& errorMessages) 
{
    ExceptionCode ec = 0;
    RefPtr<Element> reportElement = doc->createElementNS(xhtmlNamespaceURI, "parsererror", ec);
    reportElement->setAttribute(styleAttr, "white-space: pre; border: 2px solid #c77; padding: 0 1em 0 1em; margin: 1em; background-color: #fdd; color: black");
    
    RefPtr<Element> h3 = doc->createElementNS(xhtmlNamespaceURI, "h3", ec);
    reportElement->appendChild(h3.get(), ec);
    h3->appendChild(doc->createTextNode("This page contains the following errors:"), ec);
    
    RefPtr<Element> fixed = doc->createElementNS(xhtmlNamespaceURI, "div", ec);
    reportElement->appendChild(fixed.get(), ec);
    fixed->setAttribute(styleAttr, "font-family:monospace;font-size:12px");
    fixed->appendChild(doc->createTextNode(errorMessages), ec);
    
    h3 = doc->createElementNS(xhtmlNamespaceURI, "h3", ec);
    reportElement->appendChild(h3.get(), ec);
    h3->appendChild(doc->createTextNode("Below is a rendering of the page up to the first error."), ec);
    
    return reportElement;
}

void XMLTokenizer::insertErrorMessageBlock()
{
    // One or more errors occurred during parsing of the code. Display an error block to the user above
    // the normal content (the DOM tree is created manually and includes line/col info regarding 
    // where the errors are located)

    // Create elements for display
    ExceptionCode ec = 0;
    Document *doc = m_doc;
    Node* documentElement = doc->documentElement();
    if (!documentElement) {
        RefPtr<Node> rootElement = doc->createElementNS(xhtmlNamespaceURI, "html", ec);
        doc->appendChild(rootElement, ec);
        RefPtr<Node> body = doc->createElementNS(xhtmlNamespaceURI, "body", ec);
        rootElement->appendChild(body, ec);
        documentElement = body.get();
    }
#ifdef SVG_SUPPORT
    else if (documentElement->namespaceURI() == SVGNames::svgNamespaceURI) {
        // Until our SVG implementation has text support, it is best if we 
        // wrap the erroneous SVG document in an xhtml document and render
        // the combined document with error messages.
        RefPtr<Node> rootElement = doc->createElementNS(xhtmlNamespaceURI, "html", ec);
        RefPtr<Node> body = doc->createElementNS(xhtmlNamespaceURI, "body", ec);
        rootElement->appendChild(body, ec);
        body->appendChild(documentElement, ec);
        doc->appendChild(rootElement.get(), ec);
        documentElement = body.get();
    }
#endif

    RefPtr<Element> reportElement = createXHTMLParserErrorHeader(doc, m_errorMessages);
    documentElement->insertBefore(reportElement, documentElement->firstChild(), ec);
#ifdef XSLT_SUPPORT
    if (doc->transformSourceDocument()) {
        RefPtr<Element> par = doc->createElementNS(xhtmlNamespaceURI, "p", ec);
        reportElement->appendChild(par, ec);
        par->setAttribute(styleAttr, "white-space: normal");
        par->appendChild(doc->createTextNode("This document was created as the result of an XSL transformation. The line and column numbers given are from the transformed result."), ec);
    }
#endif
    doc->updateRendering();
}

void XMLTokenizer::notifyFinished(CachedResource *finishedObj)
{
    ASSERT(m_pendingScript == finishedObj);
    ASSERT(m_pendingScript->accessCount() > 0);
        
    String cachedScriptUrl = m_pendingScript->url();
    String scriptSource = m_pendingScript->script();
    bool errorOccurred = m_pendingScript->errorOccurred();
    m_pendingScript->deref(this);
    m_pendingScript = 0;
    
    RefPtr<Element> e = m_scriptElement;
    m_scriptElement = 0;
    
    if (errorOccurred) 
        EventTargetNodeCast(e.get())->dispatchHTMLEvent(errorEvent, true, false);
    else {
        m_view->frame()->executeScript(cachedScriptUrl, 0, 0, scriptSource);
        EventTargetNodeCast(e.get())->dispatchHTMLEvent(loadEvent, false, false);
    }
    
    m_scriptElement = 0;
    
    if (!m_requestingScript)
        resumeParsing();
}

bool XMLTokenizer::isWaitingForScripts() const
{
    return m_pendingScript != 0;
}

#ifdef XSLT_SUPPORT
void* xmlDocPtrForString(DocLoader* docLoader, const String& source, const DeprecatedString &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.
    const UChar BOM = 0xFEFF;
    const unsigned char BOMHighByte = *reinterpret_cast<const unsigned char*>(&BOM);

    xmlGenericErrorFunc oldErrorFunc = xmlGenericError;
    void* oldErrorContext = xmlGenericErrorContext;
    
    setLoaderForLibXMLCallbacks(docLoader);        
    xmlSetGenericErrorFunc(0, errorFunc);
    
    xmlDocPtr sourceDoc = xmlReadMemory(reinterpret_cast<const char*>(source.characters()),
                                        source.length() * sizeof(UChar),
                                        url.ascii(),
                                        BOMHighByte == 0xFF ? "UTF-16LE" : "UTF-16BE", 
                                        XSLT_PARSE_OPTIONS);
    
    setLoaderForLibXMLCallbacks(0);
    xmlSetGenericErrorFunc(oldErrorContext, oldErrorFunc);
    
    return sourceDoc;
}
#endif

Tokenizer *newXMLTokenizer(Document *d, FrameView *v)
{
    return new XMLTokenizer(d, v);
}

int XMLTokenizer::lineNumber() const
{
    return m_context->input->line;
}

int XMLTokenizer::columnNumber() const
{
    return m_context->input->col;
}

void XMLTokenizer::stopParsing()
{
    Tokenizer::stopParsing();
    xmlStopParser(m_context);
}

void XMLTokenizer::pauseParsing()
{
    if (m_parsingFragment)
        return;
    
    m_parserPaused = true;
}

void XMLTokenizer::resumeParsing()
{
    ASSERT(m_parserPaused);
    
    m_parserPaused = false;
    
    // First, execute any pending callbacks
    while (!m_pendingCallbacks->isEmpty()) {
        m_pendingCallbacks->callAndRemoveFirstCallback(this);
        
        // A callback paused the parser
        if (m_parserPaused)
            return;
    }
    
    // Then, write any pending data
    SegmentedString rest = m_pendingSrc;
    m_pendingSrc.clear();
    write(rest, false);

    // 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();
}

static void balancedStartElementNsHandler(void *closure, const xmlChar *localname, const xmlChar *prefix, const xmlChar *uri, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, const xmlChar **libxmlAttributes)
{
   static_cast<XMLTokenizer *>(closure)->startElementNs(localname, prefix, uri, nb_namespaces, namespaces, nb_attributes, nb_defaulted, libxmlAttributes);
}

static void balancedEndElementNsHandler(void *closure, const xmlChar *localname, const xmlChar *prefix, const xmlChar *uri)
{
    static_cast<XMLTokenizer *>(closure)->endElementNs();
}

static void balancedCharactersHandler(void *closure, const xmlChar *s, int len)
{
    static_cast<XMLTokenizer *>(closure)->characters(s, len);
}

static void balancedProcessingInstructionHandler(void *closure, const xmlChar *target, const xmlChar *data)
{
    static_cast<XMLTokenizer *>(closure)->processingInstruction(target, data);
}

static void balancedCdataBlockHandler(void *closure, const xmlChar *s, int len)
{
    static_cast<XMLTokenizer *>(closure)->cdataBlock(s, len);
}

static void balancedCommentHandler(void *closure, const xmlChar *comment)
{
    static_cast<XMLTokenizer *>(closure)->comment(comment);
}

static void balancedWarningHandler(void *closure, const char *message, ...)
{
    va_list args;
    va_start(args, message);
    static_cast<XMLTokenizer *>(closure)->error(XMLTokenizer::warning, message, args);
    va_end(args);
}

bool parseXMLDocumentFragment(const String &string, DocumentFragment *fragment, Element *parent)
{
    XMLTokenizer tokenizer(fragment, parent);
    
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));

    sax.characters = balancedCharactersHandler;
    sax.processingInstruction = balancedProcessingInstructionHandler;
    sax.startElementNs = balancedStartElementNsHandler;
    sax.endElementNs = balancedEndElementNsHandler;
    sax.cdataBlock = balancedCdataBlockHandler;
    sax.ignorableWhitespace = balancedCdataBlockHandler;
    sax.comment = balancedCommentHandler;
    sax.warning = balancedWarningHandler;
    sax.initialized = XML_SAX2_MAGIC;
    
    int result = xmlParseBalancedChunkMemory(0, &sax, &tokenizer, 0, (const xmlChar*)(const char*)(string.utf8()), 0);
    return result == 0;
}

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

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


static void attributesStartElementNsHandler(void *closure, const xmlChar *xmlLocalName, const xmlChar *xmlPrefix, const xmlChar *xmlURI, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, 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 < nb_attributes; 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;
    xmlParserCtxtPtr parser = createStringParser(&sax, &state);
    String parseString = "<?xml version=\"1.0\"?><attrs " + string + " />";
    xmlParseChunk(parser, reinterpret_cast<const char*>(parseString.characters()), parseString.length() * sizeof(UChar), 1);
    if (parser->myDoc)
        xmlFreeDoc(parser->myDoc);
    xmlFreeParserCtxt(parser);

    attrsOK = state.gotAttributes;
    return state.attributes;
}

}