WebCore/loader/MainResourceLoader.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "MainResourceLoader.h"

 #include "DocumentLoader.h"
 #include "Frame.h"
 #include "FrameLoader.h"
 #include "FrameLoaderClient.h"
 #include "HTMLFormElement.h"
 #include "ResourceError.h"
 #include "ResourceHandle.h"

 // FIXME: More that is in common with SubresourceLoader should move up into ResourceLoader.

 namespace WebCore {

 MainResourceLoader::MainResourceLoader(Frame* frame)
     : ResourceLoader(frame, true)
     , m_dataLoadTimer(this, &MainResourceLoader::handleDataLoadNow)
     , m_loadingMultipartContent(false)
     , m_waitingForContentPolicy(false)
 {
 }

 MainResourceLoader::~MainResourceLoader()
 {
 }

 PassRefPtr<MainResourceLoader> MainResourceLoader::create(Frame* frame)
 {
     return new MainResourceLoader(frame);
 }

 void MainResourceLoader::receivedError(const ResourceError& error)
 {
     // Calling receivedMainResourceError will likely result in the last reference to this object to go away.
     RefPtr<MainResourceLoader> protect(this);
     RefPtr<Frame> protectFrame(m_frame);

     if (!cancelled()) {
         ASSERT(!reachedTerminalState());
         frameLoader()->didFailToLoad(this, error);
     }

     frameLoader()->receivedMainResourceError(error, true);

     if (!cancelled()) {
         releaseResources();
     }

     ASSERT(reachedTerminalState());
 }

 void MainResourceLoader::didCancel(const ResourceError& error)
 {
     m_dataLoadTimer.stop();

     // Calling receivedMainResourceError will likely result in the last reference to this object to go away.
     RefPtr<MainResourceLoader> protect(this);

     if (m_waitingForContentPolicy) {
         frameLoader()->cancelContentPolicyCheck();
         ASSERT(m_waitingForContentPolicy);
         m_waitingForContentPolicy = false;
         deref(); // balances ref in didReceiveResponse
     }
     frameLoader()->receivedMainResourceError(error, true);
     ResourceLoader::didCancel(error);
 }

 ResourceError MainResourceLoader::interruptionForPolicyChangeError() const
 {
     return frameLoader()->interruptionForPolicyChangeError(request());
 }

 void MainResourceLoader::stopLoadingForPolicyChange()
 {
     cancel(interruptionForPolicyChangeError());
 }

 void MainResourceLoader::callContinueAfterNavigationPolicy(void* argument, const ResourceRequest& request, PassRefPtr<FormState>, bool shouldContinue)
 {
     static_cast<MainResourceLoader*>(argument)->continueAfterNavigationPolicy(request, shouldContinue);
 }

 void MainResourceLoader::continueAfterNavigationPolicy(const ResourceRequest& request, bool shouldContinue)
 {
     if (!shouldContinue)
         stopLoadingForPolicyChange();
     deref(); // balances ref in willSendRequest
 }

 bool MainResourceLoader::isPostOrRedirectAfterPost(const ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
 {
     if (newRequest.httpMethod() == "POST")
         return true;

     int status = redirectResponse.httpStatusCode();
     if (((status >= 301 && status <= 303) || status == 307)
         && frameLoader()->initialRequest().httpMethod() == "POST")
         return true;

     return false;
 }

 void MainResourceLoader::addData(const char* data, int length, bool allAtOnce)
 {
     ResourceLoader::addData(data, length, allAtOnce);
     frameLoader()->receivedData(data, length);
 }

 void MainResourceLoader::willSendRequest(ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
 {
     // Note that there are no asserts here as there are for the other callbacks. This is due to the
     // fact that this "callback" is sent when starting every load, and the state of callback
     // deferrals plays less of a part in this function in preventing the bad behavior deferring
     // callbacks is meant to prevent.
     ASSERT(!newRequest.isNull());

     // The additional processing can do anything including possibly removing the last
     // reference to this object; one example of this is 3266216.
     RefPtr<MainResourceLoader> protect(this);

     // Update cookie policy base URL as URL changes, except for subframes, which use the
     // URL of the main frame which doesn't change when we redirect.
     if (frameLoader()->isLoadingMainFrame())
         newRequest.setMainDocumentURL(newRequest.url());

     // If we're fielding a redirect in response to a POST, force a load from origin, since
     // this is a common site technique to return to a page viewing some data that the POST
     // just modified.
     // Also, POST requests always load from origin, but this does not affect subresources.
     if (newRequest.cachePolicy() == UseProtocolCachePolicy && isPostOrRedirectAfterPost(newRequest, redirectResponse))
         newRequest.setCachePolicy(ReloadIgnoringCacheData);

     if (!newRequest.isNull()) {
         ResourceLoader::willSendRequest(newRequest, redirectResponse);
         setRequest(newRequest);
     }

     // Don't set this on the first request. It is set when the main load was started.
     m_documentLoader->setRequest(newRequest);

     ref(); // balanced by deref in continueAfterNavigationPolicy
     frameLoader()->checkNavigationPolicy(newRequest, callContinueAfterNavigationPolicy, this);
 }

 static bool shouldLoadAsEmptyDocument(const KURL& URL)
 {
     return URL.isEmpty() || equalIgnoringCase(String(URL.protocol()), "about");
 }

 void MainResourceLoader::continueAfterContentPolicy(PolicyAction contentPolicy, const ResourceResponse& r)
 {
     KURL url = request().url();
     const String& mimeType = r.mimeType();

     switch (contentPolicy) {
     case PolicyUse: {
         // Prevent remote web archives from loading because they can claim to be from any domain and thus avoid cross-domain security checks (4120255).
         bool isRemoteWebArchive = equalIgnoringCase("application/x-webarchive", mimeType) && !m_substituteData.isValid() && !url.isLocalFile();
         if (!frameLoader()->canShowMIMEType(mimeType) || isRemoteWebArchive) {
             frameLoader()->cannotShowMIMEType(r);
             // Check reachedTerminalState since the load may have already been cancelled inside of _handleUnimplementablePolicyWithErrorCode::.
             if (!reachedTerminalState())
                 stopLoadingForPolicyChange();
             return;
         }
         break;
     }

     case PolicyDownload:
         frameLoader()->client()->download(m_handle.get(), request(), m_handle.get()->request(), r);
         receivedError(interruptionForPolicyChangeError());
         return;

     case PolicyIgnore:
         stopLoadingForPolicyChange();
         return;

     default:
         ASSERT_NOT_REACHED();
     }

     RefPtr<MainResourceLoader> protect(this);

     if (r.isHTTP()) {
         int status = r.httpStatusCode();
         if (status < 200 || status >= 300) {
             bool hostedByObject = frameLoader()->isHostedByObjectElement();

             frameLoader()->handleFallbackContent();
             // object elements are no longer rendered after we fallback, so don't
             // keep trying to process data from their load

             if (hostedByObject)
                 cancel();
         }
     }

     // we may have cancelled this load as part of switching to fallback content
     if (!reachedTerminalState())
         ResourceLoader::didReceiveResponse(r);

     if (frameLoader() && !frameLoader()->isStopping())
         if (m_substituteData.isValid()) {
             if (m_substituteData.content()->size())
                 didReceiveData(m_substituteData.content()->data(), m_substituteData.content()->size(), m_substituteData.content()->size(), true);
             if (frameLoader() && !frameLoader()->isStopping())
                 didFinishLoading();
         } else if (shouldLoadAsEmptyDocument(url) || frameLoader()->representationExistsForURLScheme(url.protocol()))
             didFinishLoading();
 }

 void MainResourceLoader::callContinueAfterContentPolicy(void* argument, PolicyAction policy)
 {
     static_cast<MainResourceLoader*>(argument)->continueAfterContentPolicy(policy);
 }

 void MainResourceLoader::continueAfterContentPolicy(PolicyAction policy)
 {
     ASSERT(m_waitingForContentPolicy);
     m_waitingForContentPolicy = false;
     if (frameLoader() && !frameLoader()->isStopping())
         continueAfterContentPolicy(policy, m_response);
     deref(); // balances ref in didReceiveResponse
 }

 void MainResourceLoader::didReceiveResponse(const ResourceResponse& r)
 {
     ASSERT(shouldLoadAsEmptyDocument(r.url()) || !defersLoading());

     if (m_loadingMultipartContent) {
         frameLoader()->setupForReplaceByMIMEType(r.mimeType());
         clearResourceData();
     }

     if (r.isMultipart())
         m_loadingMultipartContent = true;

     // The additional processing can do anything including possibly removing the last
     // reference to this object; one example of this is 3266216.
     RefPtr<MainResourceLoader> protect(this);

     m_documentLoader->setResponse(r);

     m_response = r;

     ASSERT(!m_waitingForContentPolicy);
     m_waitingForContentPolicy = true;
     ref(); // balanced by deref in continueAfterContentPolicy and didCancel
     frameLoader()->checkContentPolicy(m_response.mimeType(), callContinueAfterContentPolicy, this);
 }

 void MainResourceLoader::didReceiveData(const char* data, int length, long long lengthReceived, bool allAtOnce)
 {
     ASSERT(data);
     ASSERT(length != 0);
     ASSERT(!defersLoading());

     // The additional processing can do anything including possibly removing the last
     // reference to this object; one example of this is 3266216.
     RefPtr<MainResourceLoader> protect(this);

     ResourceLoader::didReceiveData(data, length, lengthReceived, allAtOnce);
 }

 void MainResourceLoader::didFinishLoading()
 {
     ASSERT(shouldLoadAsEmptyDocument(frameLoader()->URL()) || !defersLoading());

     // The additional processing can do anything including possibly removing the last
     // reference to this object.
     RefPtr<MainResourceLoader> protect(this);

     frameLoader()->finishedLoading();
     ResourceLoader::didFinishLoading();
 }

 void MainResourceLoader::didFail(const ResourceError& error)
 {
     ASSERT(!defersLoading());

     receivedError(error);
 }

 void MainResourceLoader::handleEmptyLoad(const KURL& url, bool forURLScheme)
 {
     String mimeType;
     if (forURLScheme)
         mimeType = frameLoader()->generatedMIMETypeForURLScheme(url.protocol());
     else
         mimeType = "text/html";

     ResourceResponse response(url, mimeType, 0, String(), String());
     didReceiveResponse(response);
 }

 void MainResourceLoader::handleDataLoadNow(Timer<MainResourceLoader>*)
 {
     RefPtr<MainResourceLoader> protect(this);

     KURL url = m_substituteData.responseURL();
     if (url.isEmpty())
         url = m_initialRequest.url();

     ResourceResponse response(url, m_substituteData.mimeType(), m_substituteData.content()->size(), m_substituteData.textEncoding(), "");
     didReceiveResponse(response);
 }

 void MainResourceLoader::handleDataLoadSoon(ResourceRequest& r)
 {
     m_initialRequest = r;

     if (m_documentLoader->deferMainResourceDataLoad())
         m_dataLoadTimer.startOneShot(0);
     else
         handleDataLoadNow(0);
 }

 bool MainResourceLoader::loadNow(ResourceRequest& r)
 {
     bool shouldLoadEmptyBeforeRedirect = shouldLoadAsEmptyDocument(r.url());

     ASSERT(!m_handle);
     ASSERT(shouldLoadEmptyBeforeRedirect || !defersLoading());

     // Send this synthetic delegate callback since clients expect it, and
     // we no longer send the callback from within NSURLConnection for
     // initial requests.
     willSendRequest(r, ResourceResponse());

     // <rdar://problem/4801066>
     // willSendRequest() is liable to make the call to frameLoader() return NULL, so we need to check that here
     if (!frameLoader())
         return false;

     const KURL& url = r.url();
     bool shouldLoadEmpty = shouldLoadAsEmptyDocument(url) && !m_substituteData.isValid();

     if (shouldLoadEmptyBeforeRedirect && !shouldLoadEmpty && defersLoading())
         return true;

     if (m_substituteData.isValid())
         handleDataLoadSoon(r);
     else if (shouldLoadEmpty || frameLoader()->representationExistsForURLScheme(url.protocol()))
         handleEmptyLoad(url, !shouldLoadEmpty);
     else
         m_handle = ResourceHandle::create(r, this, m_frame.get(), false, true);

     return false;
 }

 bool MainResourceLoader::load(const ResourceRequest& r, const SubstituteData&  substituteData)
 {
     ASSERT(!m_handle);

     m_substituteData = substituteData;

     ResourceRequest request(r);
     bool defer = defersLoading();
     if (defer) {
         bool shouldLoadEmpty = shouldLoadAsEmptyDocument(r.url());
         if (shouldLoadEmpty)
             defer = false;
     }
     if (!defer) {
         if (loadNow(request)) {
             // Started as an empty document, but was redirected to something non-empty.
             ASSERT(defersLoading());
             defer = true;
         }
     }
     if (defer)
         m_initialRequest = request;

     return true;
 }

 void MainResourceLoader::setDefersLoading(bool defers)
 {
     ResourceLoader::setDefersLoading(defers);

     if (defers) {
         if (m_dataLoadTimer.isActive())
             m_dataLoadTimer.stop();
     } else {
         if (m_initialRequest.isNull())
             return;

         if (m_substituteData.isValid() &&
             m_documentLoader->deferMainResourceDataLoad())
                 m_dataLoadTimer.startOneShot(0);
         else {
             ResourceRequest r(m_initialRequest);
             m_initialRequest = ResourceRequest();
             loadNow(r);
         }
     }
 }

 }
	/*
	* Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
	* its contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "MainResourceLoader.h"

	#include "DocumentLoader.h"
	#include "Frame.h"
	#include "FrameLoader.h"
	#include "FrameLoaderClient.h"
	#include "HTMLFormElement.h"
	#include "ResourceError.h"
	#include "ResourceHandle.h"

	// FIXME: More that is in common with SubresourceLoader should move up into ResourceLoader.

	namespace WebCore {

	MainResourceLoader::MainResourceLoader(Frame* frame)
	: ResourceLoader(frame, true)
	, m_dataLoadTimer(this, &MainResourceLoader::handleDataLoadNow)
	, m_loadingMultipartContent(false)
	, m_waitingForContentPolicy(false)
	{
	}

	MainResourceLoader::~MainResourceLoader()
	{
	}

	PassRefPtr<MainResourceLoader> MainResourceLoader::create(Frame* frame)
	{
	return new MainResourceLoader(frame);
	}

	void MainResourceLoader::receivedError(const ResourceError& error)
	{
	// Calling receivedMainResourceError will likely result in the last reference to this object to go away.
	RefPtr<MainResourceLoader> protect(this);
	RefPtr<Frame> protectFrame(m_frame);

	if (!cancelled()) {
	ASSERT(!reachedTerminalState());
	frameLoader()->didFailToLoad(this, error);
	}

	frameLoader()->receivedMainResourceError(error, true);

	if (!cancelled()) {
	releaseResources();
	}

	ASSERT(reachedTerminalState());
	}

	void MainResourceLoader::didCancel(const ResourceError& error)
	{
	m_dataLoadTimer.stop();

	// Calling receivedMainResourceError will likely result in the last reference to this object to go away.
	RefPtr<MainResourceLoader> protect(this);

	if (m_waitingForContentPolicy) {
	frameLoader()->cancelContentPolicyCheck();
	ASSERT(m_waitingForContentPolicy);
	m_waitingForContentPolicy = false;
	deref(); // balances ref in didReceiveResponse
	}
	frameLoader()->receivedMainResourceError(error, true);
	ResourceLoader::didCancel(error);
	}

	ResourceError MainResourceLoader::interruptionForPolicyChangeError() const
	{
	return frameLoader()->interruptionForPolicyChangeError(request());
	}

	void MainResourceLoader::stopLoadingForPolicyChange()
	{
	cancel(interruptionForPolicyChangeError());
	}

	void MainResourceLoader::callContinueAfterNavigationPolicy(void* argument, const ResourceRequest& request, PassRefPtr<FormState>, bool shouldContinue)
	{
	static_cast<MainResourceLoader*>(argument)->continueAfterNavigationPolicy(request, shouldContinue);
	}

	void MainResourceLoader::continueAfterNavigationPolicy(const ResourceRequest& request, bool shouldContinue)
	{
	if (!shouldContinue)
	stopLoadingForPolicyChange();
	deref(); // balances ref in willSendRequest
	}

	bool MainResourceLoader::isPostOrRedirectAfterPost(const ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
	{
	if (newRequest.httpMethod() == "POST")
	return true;

	int status = redirectResponse.httpStatusCode();
	if (((status >= 301 && status <= 303) \|\| status == 307)
	&& frameLoader()->initialRequest().httpMethod() == "POST")
	return true;

	return false;
	}

	void MainResourceLoader::addData(const char* data, int length, bool allAtOnce)
	{
	ResourceLoader::addData(data, length, allAtOnce);
	frameLoader()->receivedData(data, length);
	}

	void MainResourceLoader::willSendRequest(ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
	{
	// Note that there are no asserts here as there are for the other callbacks. This is due to the
	// fact that this "callback" is sent when starting every load, and the state of callback
	// deferrals plays less of a part in this function in preventing the bad behavior deferring
	// callbacks is meant to prevent.
	ASSERT(!newRequest.isNull());

	// The additional processing can do anything including possibly removing the last
	// reference to this object; one example of this is 3266216.
	RefPtr<MainResourceLoader> protect(this);

	// Update cookie policy base URL as URL changes, except for subframes, which use the
	// URL of the main frame which doesn't change when we redirect.
	if (frameLoader()->isLoadingMainFrame())
	newRequest.setMainDocumentURL(newRequest.url());

	// If we're fielding a redirect in response to a POST, force a load from origin, since
	// this is a common site technique to return to a page viewing some data that the POST
	// just modified.
	// Also, POST requests always load from origin, but this does not affect subresources.
	if (newRequest.cachePolicy() == UseProtocolCachePolicy && isPostOrRedirectAfterPost(newRequest, redirectResponse))
	newRequest.setCachePolicy(ReloadIgnoringCacheData);

	if (!newRequest.isNull()) {
	ResourceLoader::willSendRequest(newRequest, redirectResponse);
	setRequest(newRequest);
	}

	// Don't set this on the first request. It is set when the main load was started.
	m_documentLoader->setRequest(newRequest);

	ref(); // balanced by deref in continueAfterNavigationPolicy
	frameLoader()->checkNavigationPolicy(newRequest, callContinueAfterNavigationPolicy, this);
	}

	static bool shouldLoadAsEmptyDocument(const KURL& URL)
	{
	return URL.isEmpty() \|\| equalIgnoringCase(String(URL.protocol()), "about");
	}

	void MainResourceLoader::continueAfterContentPolicy(PolicyAction contentPolicy, const ResourceResponse& r)
	{
	KURL url = request().url();
	const String& mimeType = r.mimeType();

	switch (contentPolicy) {
	case PolicyUse: {
	// Prevent remote web archives from loading because they can claim to be from any domain and thus avoid cross-domain security checks (4120255).
	bool isRemoteWebArchive = equalIgnoringCase("application/x-webarchive", mimeType) && !m_substituteData.isValid() && !url.isLocalFile();
	if (!frameLoader()->canShowMIMEType(mimeType) \|\| isRemoteWebArchive) {
	frameLoader()->cannotShowMIMEType(r);
	// Check reachedTerminalState since the load may have already been cancelled inside of _handleUnimplementablePolicyWithErrorCode::.
	if (!reachedTerminalState())
	stopLoadingForPolicyChange();
	return;
	}
	break;
	}

	case PolicyDownload:
	frameLoader()->client()->download(m_handle.get(), request(), m_handle.get()->request(), r);
	receivedError(interruptionForPolicyChangeError());
	return;

	case PolicyIgnore:
	stopLoadingForPolicyChange();
	return;

	default:
	ASSERT_NOT_REACHED();
	}

	RefPtr<MainResourceLoader> protect(this);

	if (r.isHTTP()) {
	int status = r.httpStatusCode();
	if (status < 200 \|\| status >= 300) {
	bool hostedByObject = frameLoader()->isHostedByObjectElement();

	frameLoader()->handleFallbackContent();
	// object elements are no longer rendered after we fallback, so don't
	// keep trying to process data from their load

	if (hostedByObject)
	cancel();
	}
	}

	// we may have cancelled this load as part of switching to fallback content
	if (!reachedTerminalState())
	ResourceLoader::didReceiveResponse(r);

	if (frameLoader() && !frameLoader()->isStopping())
	if (m_substituteData.isValid()) {
	if (m_substituteData.content()->size())
	didReceiveData(m_substituteData.content()->data(), m_substituteData.content()->size(), m_substituteData.content()->size(), true);
	if (frameLoader() && !frameLoader()->isStopping())
	didFinishLoading();
	} else if (shouldLoadAsEmptyDocument(url) \|\| frameLoader()->representationExistsForURLScheme(url.protocol()))
	didFinishLoading();
	}

	void MainResourceLoader::callContinueAfterContentPolicy(void* argument, PolicyAction policy)
	{
	static_cast<MainResourceLoader*>(argument)->continueAfterContentPolicy(policy);
	}

	void MainResourceLoader::continueAfterContentPolicy(PolicyAction policy)
	{
	ASSERT(m_waitingForContentPolicy);
	m_waitingForContentPolicy = false;
	if (frameLoader() && !frameLoader()->isStopping())
	continueAfterContentPolicy(policy, m_response);
	deref(); // balances ref in didReceiveResponse
	}

	void MainResourceLoader::didReceiveResponse(const ResourceResponse& r)
	{
	ASSERT(shouldLoadAsEmptyDocument(r.url()) \|\| !defersLoading());

	if (m_loadingMultipartContent) {
	frameLoader()->setupForReplaceByMIMEType(r.mimeType());
	clearResourceData();
	}

	if (r.isMultipart())
	m_loadingMultipartContent = true;

	// The additional processing can do anything including possibly removing the last
	// reference to this object; one example of this is 3266216.
	RefPtr<MainResourceLoader> protect(this);

	m_documentLoader->setResponse(r);

	m_response = r;

	ASSERT(!m_waitingForContentPolicy);
	m_waitingForContentPolicy = true;
	ref(); // balanced by deref in continueAfterContentPolicy and didCancel
	frameLoader()->checkContentPolicy(m_response.mimeType(), callContinueAfterContentPolicy, this);
	}

	void MainResourceLoader::didReceiveData(const char* data, int length, long long lengthReceived, bool allAtOnce)
	{
	ASSERT(data);
	ASSERT(length != 0);
	ASSERT(!defersLoading());

	// The additional processing can do anything including possibly removing the last
	// reference to this object; one example of this is 3266216.
	RefPtr<MainResourceLoader> protect(this);

	ResourceLoader::didReceiveData(data, length, lengthReceived, allAtOnce);
	}

	void MainResourceLoader::didFinishLoading()
	{
	ASSERT(shouldLoadAsEmptyDocument(frameLoader()->URL()) \|\| !defersLoading());

	// The additional processing can do anything including possibly removing the last
	// reference to this object.
	RefPtr<MainResourceLoader> protect(this);

	frameLoader()->finishedLoading();
	ResourceLoader::didFinishLoading();
	}

	void MainResourceLoader::didFail(const ResourceError& error)
	{
	ASSERT(!defersLoading());

	receivedError(error);
	}

	void MainResourceLoader::handleEmptyLoad(const KURL& url, bool forURLScheme)
	{
	String mimeType;
	if (forURLScheme)
	mimeType = frameLoader()->generatedMIMETypeForURLScheme(url.protocol());
	else
	mimeType = "text/html";

	ResourceResponse response(url, mimeType, 0, String(), String());
	didReceiveResponse(response);
	}

	void MainResourceLoader::handleDataLoadNow(Timer<MainResourceLoader>*)
	{
	RefPtr<MainResourceLoader> protect(this);

	KURL url = m_substituteData.responseURL();
	if (url.isEmpty())
	url = m_initialRequest.url();

	ResourceResponse response(url, m_substituteData.mimeType(), m_substituteData.content()->size(), m_substituteData.textEncoding(), "");
	didReceiveResponse(response);
	}

	void MainResourceLoader::handleDataLoadSoon(ResourceRequest& r)
	{
	m_initialRequest = r;

	if (m_documentLoader->deferMainResourceDataLoad())
	m_dataLoadTimer.startOneShot(0);
	else
	handleDataLoadNow(0);
	}

	bool MainResourceLoader::loadNow(ResourceRequest& r)
	{
	bool shouldLoadEmptyBeforeRedirect = shouldLoadAsEmptyDocument(r.url());

	ASSERT(!m_handle);
	ASSERT(shouldLoadEmptyBeforeRedirect \|\| !defersLoading());

	// Send this synthetic delegate callback since clients expect it, and
	// we no longer send the callback from within NSURLConnection for
	// initial requests.
	willSendRequest(r, ResourceResponse());

	// <rdar://problem/4801066>
	// willSendRequest() is liable to make the call to frameLoader() return NULL, so we need to check that here
	if (!frameLoader())
	return false;

	const KURL& url = r.url();
	bool shouldLoadEmpty = shouldLoadAsEmptyDocument(url) && !m_substituteData.isValid();

	if (shouldLoadEmptyBeforeRedirect && !shouldLoadEmpty && defersLoading())
	return true;

	if (m_substituteData.isValid())
	handleDataLoadSoon(r);
	else if (shouldLoadEmpty \|\| frameLoader()->representationExistsForURLScheme(url.protocol()))
	handleEmptyLoad(url, !shouldLoadEmpty);
	else
	m_handle = ResourceHandle::create(r, this, m_frame.get(), false, true);

	return false;
	}

	bool MainResourceLoader::load(const ResourceRequest& r, const SubstituteData& substituteData)
	{
	ASSERT(!m_handle);

	m_substituteData = substituteData;

	ResourceRequest request(r);
	bool defer = defersLoading();
	if (defer) {
	bool shouldLoadEmpty = shouldLoadAsEmptyDocument(r.url());
	if (shouldLoadEmpty)
	defer = false;
	}
	if (!defer) {
	if (loadNow(request)) {
	// Started as an empty document, but was redirected to something non-empty.
	ASSERT(defersLoading());
	defer = true;
	}
	}
	if (defer)
	m_initialRequest = request;

	return true;
	}

	void MainResourceLoader::setDefersLoading(bool defers)
	{
	ResourceLoader::setDefersLoading(defers);

	if (defers) {
	if (m_dataLoadTimer.isActive())
	m_dataLoadTimer.stop();
	} else {
	if (m_initialRequest.isNull())
	return;

	if (m_substituteData.isValid() &&
	m_documentLoader->deferMainResourceDataLoad())
	m_dataLoadTimer.startOneShot(0);
	else {
	ResourceRequest r(m_initialRequest);
	m_initialRequest = ResourceRequest();
	loadNow(r);
	}
	}
	}

	}