Notify when resource with error code >= 400 is finished.

Source/core/fetch/ResourceLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2007 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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.
@@ skipping 68 matching lines @@
 {
 }
 
 ResourceLoader::~ResourceLoader()
 {
     ASSERT(m_state == Terminated);
 }
 
 void ResourceLoader::releaseResources()
 {
+    ASSERT(m_notifiedLoadComplete);
     ASSERT(m_state != Terminated);
     m_requestCountTracker.clear();
     m_host->didLoadResource(m_resource);
     if (m_state == Terminated)
         return;
     m_resource->clearLoader();
     m_host->willTerminateResourceLoader(this);
 
     ASSERT(m_state != Terminated);
 
@@ skipping 141 matching lines @@
     if (m_state == Initialized)
         m_state = Finishing;
     m_resource->setResourceError(nonNullError);
 
     if (m_loader) {
         m_connectionState = ConnectionStateCanceled;
         m_loader->cancel();
         m_loader.clear();
     }
 
-    m_host->didFailLoading(m_resource, nonNullError);
+    if (!m_notifiedLoadComplete) {
+        m_notifiedLoadComplete = true;
+        m_host->didFailLoading(m_resource, nonNullError);
+    }
 
     if (m_state == Finishing)
         m_resource->error(Resource::LoadError);
     if (m_state != Terminated)
         releaseResources();
 }
 
 void ResourceLoader::willSendRequest(blink::WebURLLoader*, blink::WebURLRequest& passedRequest, const blink::WebURLResponse& passedRedirectResponse)
 {
     RefPtr<ResourceLoader> protect(this);
@@ skipping 84 matching lines @@
         }
     } else if (isMultipartPayload) {
         // Since a subresource loader does not load multipart sections progressively, data was delivered to the loader all at once.
         // After the first multipart section is complete, signal to delegates that this load is "finished"
         m_host->subresourceLoaderFinishedLoadingOnePart(this);
         didFinishLoadingOnePart(0);
     }
 
     if (m_resource->response().httpStatusCode() < 400 || m_resource->shouldIgnoreHTTPStatusCodeErrors())
         return;
+
     m_state = Finishing;
     m_resource->error(Resource::LoadError);
+    if (!m_notifiedLoadComplete) {

[Nate Chapin, 2014/01/31 17:25:52]

I'm not sure this is safe. Specifically, if m_resource->error() triggers an
event, it's possible that this ResourceLoader will get cancelled synchronously
inside. If that happens, because m_state is already Finishing, cancel() will
call releaseResources() and clear m_host without setting m_notifiedLoadComplete
to true.

I suspect that here and throughout, we should make sure the
m_host->didFinishLoading() or m_host->didFailLoading() call happens before the
m_resource->finish() or m_resource->error().

[eustas, 2014/02/03 12:56:06]

Done.

+        m_notifiedLoadComplete = true;
+        m_host->didFinishLoading(m_resource, monotonicallyIncreasingTime());
+    }
     cancel();
 }
 
 void ResourceLoader::didReceiveData(blink::WebURLLoader*, const char* data, int length, int encodedDataLength)
 {
     RELEASE_ASSERT(m_connectionState == ConnectionStateReceivedResponse || m_connectionState == ConnectionStateReceivingData);
     m_connectionState = ConnectionStateReceivingData;
 
     // It is possible to receive data on uninitialized resources if it had an error status code, and we are running a nested message
     // loop. When this occurs, ignoring the data is the correct action.
@@ skipping 89 matching lines @@
     didReceiveResponse(0, responseOut);
     if (m_state == Terminated)
         return;
     RefPtr<ResourceLoadInfo> resourceLoadInfo = responseOut.toResourceResponse().resourceLoadInfo();
     m_host->didReceiveData(m_resource, dataOut.data(), dataOut.size(), resourceLoadInfo ? resourceLoadInfo->encodedDataLength : -1);
     m_resource->setResourceBuffer(dataOut);
     didFinishLoading(0, monotonicallyIncreasingTime());
 }
 
 }