Diff
Modified: releases/WebKitGTK/webkit-2.18/Source/WebCore/ChangeLog (223512 => 223513)
--- releases/WebKitGTK/webkit-2.18/Source/WebCore/ChangeLog 2017-10-17 10:02:01 UTC (rev 223512)
+++ releases/WebKitGTK/webkit-2.18/Source/WebCore/ChangeLog 2017-10-17 10:05:36 UTC (rev 223513)
@@ -1,3 +1,25 @@
+2017-10-05 Miguel Gomez <[email protected]>
+
+ [GTK][WPE] GIFImageDecoder never clears decoded frames even when told to do so
+ https://bugs.webkit.org/show_bug.cgi?id=177864
+
+ Reviewed by Carlos Garcia Campos.
+
+ Fix GIFImageDecoder::clearFrameBufferCache() so it really deletes decoded buffers, and modify
+ GIFImageDecoder to be able to decode frames that are not requested in the expected order.
+
+ Covered by existent tests.
+
+ * platform/image-decoders/gif/GIFImageDecoder.cpp:
+ (WebCore::GIFImageDecoder::findFirstRequiredFrameToDecode):
+ (WebCore::GIFImageDecoder::frameBufferAtIndex):
+ (WebCore::GIFImageDecoder::clearFrameBufferCache):
+ * platform/image-decoders/gif/GIFImageDecoder.h:
+ * platform/image-decoders/gif/GIFImageReader.cpp:
+ (GIFImageReader::decode):
+ * platform/image-decoders/gif/GIFImageReader.h:
+ (GIFImageReader::frameContext const):
+
2017-10-05 Zan Dobersek <[email protected]>
Align BitmapImage::LargeAnimationCutoff to a megabyte value
Modified: releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageDecoder.cpp (223512 => 223513)
--- releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageDecoder.cpp 2017-10-17 10:02:01 UTC (rev 223512)
+++ releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageDecoder.cpp 2017-10-17 10:05:36 UTC (rev 223513)
@@ -101,6 +101,44 @@
return m_repetitionCount;
}
+size_t GIFImageDecoder::findFirstRequiredFrameToDecode(size_t frameIndex)
+{
+ // The first frame doesn't depend on any other.
+ if (!frameIndex)
+ return 0;
+
+ for (size_t i = frameIndex; i > 0; --i) {
+ ImageFrame& frame = m_frameBufferCache[i - 1];
+
+ // Frames with disposal method RestoreToPrevious are useless, skip them.
+ if (frame.disposalMethod() == ImageFrame::DisposalMethod::RestoreToPrevious)
+ continue;
+
+ // At this point the disposal method can be Unspecified, DoNotDispose or RestoreToBackground.
+ // In every case, if the frame is complete we can start decoding the next one.
+ if (frame.isComplete())
+ return i;
+
+ // If the disposal method of this frame is RestoreToBackground and it fills the whole area,
+ // the next frame's backing store is initialized to transparent, so we start decoding with it.
+ if (frame.disposalMethod() == ImageFrame::DisposalMethod::RestoreToBackground) {
+ // We cannot use frame.backingStore()->frameRect() here, because it has been cleared
+ // when the frame was removed from the cache. We need to get the values from the
+ // reader context.
+ const auto* frameContext = m_reader->frameContext(i - 1);
+ ASSERT(frameContext);
+ IntRect frameRect(frameContext->xOffset, frameContext->yOffset, frameContext->width, frameContext->height);
+ // We would need to scale frameRect and check whether it fills the whole scaledSize(). But
+ // can check whether the original frameRect fills size() instead. If the frame fills the
+ // whole area then it can be decoded without dependencies.
+ if (frameRect.contains({ { }, size() }))
+ return i;
+ }
+ }
+
+ return 0;
+}
+
ImageFrame* GIFImageDecoder::frameBufferAtIndex(size_t index)
{
if (index >= frameCount())
@@ -107,8 +145,11 @@
return 0;
ImageFrame& frame = m_frameBufferCache[index];
- if (!frame.isComplete())
- decode(index + 1, GIFFullQuery, isAllDataReceived());
+ if (!frame.isComplete()) {
+ for (auto i = findFirstRequiredFrameToDecode(index); i <= index; i++)
+ decode(i + 1, GIFFullQuery, isAllDataReceived());
+ }
+
return &frame;
}
@@ -163,7 +204,7 @@
// Now |i| holds the last frame we need to preserve; clear prior frames.
for (Vector<ImageFrame>::iterator j(m_frameBufferCache.begin()); j != i; ++j) {
ASSERT(!j->isPartial());
- if (j->isInvalid())
+ if (!j->isInvalid())
j->clear();
}
}
Modified: releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageDecoder.h (223512 => 223513)
--- releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageDecoder.h 2017-10-17 10:02:01 UTC (rev 223512)
+++ releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageDecoder.h 2017-10-17 10:05:36 UTC (rev 223513)
@@ -65,6 +65,7 @@
private:
GIFImageDecoder(AlphaOption, GammaAndColorProfileOption);
void tryDecodeSize(bool allDataReceived) override { decode(0, GIFSizeQuery, allDataReceived); }
+ size_t findFirstRequiredFrameToDecode(size_t);
// If the query is GIFFullQuery, decodes the image up to (but not
// including) |haltAtFrame|. Otherwise, decodes as much as is needed to
Modified: releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageReader.cpp (223512 => 223513)
--- releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageReader.cpp 2017-10-17 10:02:01 UTC (rev 223512)
+++ releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageReader.cpp 2017-10-17 10:05:36 UTC (rev 223513)
@@ -365,9 +365,9 @@
// Already decoded frames can be deleted from the cache and then they require to be decoded again, so
// the haltAtFrame value we receive here may be lower than m_currentDecodingFrame. In this case
- // we position m_currentDecodingFrame to haltAtFrame and decode from there.
+ // we position m_currentDecodingFrame to haltAtFrame - 1 and decode from there.
// See bug https://bugs.webkit.org/show_bug.cgi?id=176089.
- m_currentDecodingFrame = std::min(m_currentDecodingFrame, static_cast<size_t>(haltAtFrame));
+ m_currentDecodingFrame = std::min(m_currentDecodingFrame, static_cast<size_t>(haltAtFrame) - 1);
while (m_currentDecodingFrame < std::min(m_frames.size(), static_cast<size_t>(haltAtFrame))) {
bool frameDecoded = false;
Modified: releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageReader.h (223512 => 223513)
--- releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageReader.h 2017-10-17 10:02:01 UTC (rev 223512)
+++ releases/WebKitGTK/webkit-2.18/Source/WebCore/platform/image-decoders/gif/GIFImageReader.h 2017-10-17 10:05:36 UTC (rev 223513)
@@ -284,6 +284,11 @@
return m_currentDecodingFrame < m_frames.size() ? m_frames[m_currentDecodingFrame].get() : 0;
}
+ const GIFFrameContext* frameContext(size_t frame) const
+ {
+ return frame < m_frames.size() ? m_frames[frame].get() : nullptr;
+ }
+
private:
bool parse(size_t dataPosition, size_t len, bool parseSizeOnly);
void setRemainingBytes(size_t);
