1 files changed, 11 insertions, 2 deletions
diff --git a/WebCore/platform/graphics/qt/ImageDecoderQt.cpp b/WebCore/platform/graphics/qt/ImageDecoderQt.cpp
index 394c7a7..cd32428 100644
--- a/WebCore/platform/graphics/qt/ImageDecoderQt.cpp
+++ b/WebCore/platform/graphics/qt/ImageDecoderQt.cpp
@@ -197,7 +197,8 @@ ImageDecoderQt* ImageDecoderQt::create(const SharedBuffer& data)
 }
 
 ImageDecoderQt::ImageDecoderQt(const QString &imageFormat)
-    : m_imageFormat(imageFormat)
+    : m_hasAlphaChannel(false)
+    , m_imageFormat(imageFormat)
 {
 }
 
@@ -212,6 +213,7 @@ bool ImageDecoderQt::hasFirstImageHeader() const
 
 void ImageDecoderQt::reset()
 {
+    m_hasAlphaChannel = false;
     m_failed = false;
     m_imageList.clear();
     m_pixmapCache.clear();
@@ -230,6 +232,9 @@ void ImageDecoderQt::setData(const IncomingData &data, bool allDataReceived)
 
     const  ReadContext::ReadResult readResult =  readContext.read(allDataReceived);
 
+    if (hasFirstImageHeader())
+        m_hasAlphaChannel = m_imageList[0].m_image.hasAlphaChannel();
+
     if (debugImageDecoderQt)
         qDebug()  << " read returns " << readResult;
 
@@ -280,7 +285,7 @@ int ImageDecoderQt::repetitionCount() const
 
 bool ImageDecoderQt::supportsAlpha() const
 {
-    return hasFirstImageHeader() && m_imageList[0].m_image.hasAlphaChannel();
+    return m_hasAlphaChannel;
 }
 
 int ImageDecoderQt::duration(size_t index) const
@@ -314,6 +319,10 @@ QPixmap* ImageDecoderQt::imageAtIndex(size_t index) const
     if (!m_pixmapCache.contains(index)) {
         m_pixmapCache.insert(index,
                              QPixmap::fromImage(m_imageList[index].m_image));
+
+        // store null image since the converted pixmap is already in pixmap cache
+        Q_ASSERT(m_imageList[index].m_imageState == ImageComplete);
+        m_imageList[index].m_image = QImage();
     }
     return  &m_pixmapCache[index];
 }