Fix ImageDecoder::frameIsCompleteAtIndex - fully received instead of decoded.

third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp

Index: third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp
diff --git a/third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp
index 5f787b50ea0044779301c303903b7c7591902ef3..008852e71d0898a0807234e843b61f8a276b6386 100644
--- a/third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp
@@ -163,6 +163,7 @@ private:
 PNGImageDecoder::PNGImageDecoder(AlphaOption alphaOption, GammaAndColorProfileOption colorOptions, size_t maxDecodedBytes, size_t offset)
     : ImageDecoder(alphaOption, colorOptions, maxDecodedBytes)
     , m_offset(offset)
+    , m_hasPixelsWithAlpha(false)
 {
 }
 
@@ -314,7 +315,6 @@ void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex,
         }
 #endif
         buffer.setStatus(ImageFrame::FramePartial);

[scroggo_chromium, 2016/05/16 20:32:08]

Previously, a partially decoded PNG file will report false for hasAlpha. With
this CL, it will return true. Please add a test for that behavior.

-        buffer.setHasAlpha(false);
 
         // For PNGs, the frame always fills the entire image.
         buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
@@ -401,8 +401,8 @@ void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex,
         }
     }
 
-    if (alphaMask != 255 && !buffer.hasAlpha())
-        buffer.setHasAlpha(true);
+    if (alphaMask != 255 && !m_hasPixelsWithAlpha)
+        m_hasPixelsWithAlpha = true;
 
     buffer.setPixelsChanged(true);
 }
@@ -412,21 +412,18 @@ void PNGImageDecoder::complete()
     if (m_frameBufferCache.isEmpty())
         return;
 
+    m_frameBufferCache[0].setHasAlpha(m_hasPixelsWithAlpha);
     m_frameBufferCache[0].setStatus(ImageFrame::FrameComplete);
 }
 
-inline bool isComplete(const PNGImageDecoder* decoder)
-{
-    return decoder->frameIsCompleteAtIndex(0);
-}
-
 void PNGImageDecoder::decode(bool onlySize)
 {
     if (failed())
         return;
 
-    if (!m_reader)
+    if (!m_reader) {

[scroggo_chromium, 2016/05/16 20:32:08]

This change is unnecessary.

[aleksandar.stojiljkovic, 2016/05/22 15:41:53]

Done.

         m_reader = adoptPtr(new PNGImageReader(this, m_offset));
+    }
 
     // If we couldn't decode the image but have received all the data, decoding
     // has failed.
@@ -434,7 +431,7 @@ void PNGImageDecoder::decode(bool onlySize)
         setFailed();
 
     // If decoding is done or failed, we don't need the PNGImageReader anymore.
-    if (isComplete(this) || failed())
+    if (frameIsCompleteAtIndex(0) || failed())
         m_reader.clear();
 }