Cancel image loads if decoding failed.

third_party/WebKit/Source/platform/graphics/ImageSource.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp.toker@collabora.co.uk>
  * Copyright (C) 2008, Google 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.
@@ skipping 33 matching lines @@
 size_t ImageSource::clearCacheExceptFrame(size_t clearExceptFrame)
 {
     return m_decoder ? m_decoder->clearCacheExceptFrame(clearExceptFrame) : 0;
 }
 
 PassRefPtr<SharedBuffer> ImageSource::data()
 {
     return m_decoder ? m_decoder->data() : nullptr;
 }
 
-void ImageSource::setData(SharedBuffer& data, bool allDataReceived)
+bool ImageSource::setData(SharedBuffer& data, bool allDataReceived)
 {
     // Create a decoder by sniffing the encoded data. If insufficient data bytes are available to
     // determine the encoded image type, no decoder is created.
     if (!m_decoder)
         m_decoder = DeferredImageDecoder::create(data, ImageDecoder::AlphaPremultiplied, ImageDecoder::GammaAndColorProfileApplied);
 
-    if (m_decoder)
+    if (m_decoder) {
         m_decoder->setData(data, allDataReceived);
+        return true;
+    }
+    // If enough data has been received to know that we won't have a valid decoded, bail.

[pdr., 2016/07/20 20:39:16]

nit: valid decoded -> valid decode

[Nate Chapin, 2016/07/20 22:50:00]

Done.

+    return data.size() < ImageDecoder::longestSignatureLength();

[pdr., 2016/07/20 20:39:16]

This signature length check is now in two places, but that shouldn't be
required. Also.. can we reach this line and return anything but false?

[Nate Chapin, 2016/07/20 22:50:00]

The failure to create a decoder could be because we have only a few bytes and
therefore might later be able to identify an image type from sniffing
(admittedly a rare case), or it might be that we are absolutely certain that we
don't have a type match. So it's almost always false, but not absolutely
guaranteed. I've updated to use the enum, which is more code churn, but is
probably cleaner overall. WDYT?

 }
 
 String ImageSource::filenameExtension() const
 {
     return m_decoder ? m_decoder->filenameExtension() : String();
 }
 
 bool ImageSource::isSizeAvailable()
 {
     return m_decoder && m_decoder->isSizeAvailable();
@@ skipping 73 matching lines @@
 {
     return m_decoder && m_decoder->frameIsCompleteAtIndex(index);
 }
 
 size_t ImageSource::frameBytesAtIndex(size_t index) const
 {
     return m_decoder ? m_decoder->frameBytesAtIndex(index) : 0;
 }
 
 } // namespace blink