REGRESSION(r91628): 3 canvas tests crash on Chromium Linux and one te…

…st fail on Chromium Mac

https://bugs.webkit.org/show_bug.cgi?id=65063

Reviewed by Darin Fisher.

Fixes crashes due to a bad cast from Image to BitmapImage on skia ports
that use BitmapImageSingleFrameSkia. In the skia port
Image::isBitmapImage() returning true does not necessarily mean that
Image is of type BitmapImage.

Covered by fast/canvas/canvas-as-image.html and many other canvas
tests.

Patch originally by Tom Hudson.

* platform/graphics/BitmapImage.h:
(WebCore::BitmapImage::currentFrameHasAlpha):
(WebCore::BitmapImage::notSolidColor):
* platform/graphics/Image.cpp:
(WebCore::Image::drawTiled):
* platform/graphics/Image.h:
(WebCore::Image::currentFrameHasAlpha):
(WebCore::Image::notSolidColor):
* platform/graphics/skia/BitmapImageSingleFrameSkia.h:
(WebCore::BitmapImageSingleFrameSkia::currentFrameHasAlpha):
(WebCore::BitmapImageSingleFrameSkia::notSolidColor):
* rendering/RenderImage.cpp:
(WebCore::RenderImage::backgroundIsObscured):

Canonical link: https://commits.webkit.org/82431@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@93441 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,34 @@
+2011-08-19  James Robinson  <jamesr@chromium.org>
+
+        REGRESSION(r91628): 3 canvas tests crash on Chromium Linux and one test fail on Chromium Mac
+        https://bugs.webkit.org/show_bug.cgi?id=65063
+
+        Reviewed by Darin Fisher.
+
+        Fixes crashes due to a bad cast from Image to BitmapImage on skia ports
+        that use BitmapImageSingleFrameSkia. In the skia port
+        Image::isBitmapImage() returning true does not necessarily mean that
+        Image is of type BitmapImage.
+
+        Covered by fast/canvas/canvas-as-image.html and many other canvas
+        tests.
+
+        Patch originally by Tom Hudson.
+
+        * platform/graphics/BitmapImage.h:
+        (WebCore::BitmapImage::currentFrameHasAlpha):
+        (WebCore::BitmapImage::notSolidColor):
+        * platform/graphics/Image.cpp:
+        (WebCore::Image::drawTiled):
+        * platform/graphics/Image.h:
+        (WebCore::Image::currentFrameHasAlpha):
+        (WebCore::Image::notSolidColor):
+        * platform/graphics/skia/BitmapImageSingleFrameSkia.h:
+        (WebCore::BitmapImageSingleFrameSkia::currentFrameHasAlpha):
+        (WebCore::BitmapImageSingleFrameSkia::notSolidColor):
+        * rendering/RenderImage.cpp:
+        (WebCore::RenderImage::backgroundIsObscured):
+
 2011-08-19  Emil A Eklund  <eae@chromium.org>
 
         Switch clipping for svg to to new layout types

Source/WebCore/platform/graphics/BitmapImage.h

@@ -159,10 +159,10 @@ class BitmapImage : public Image {
 
     virtual NativeImagePtr nativeImageForCurrentFrame() { return frameAtIndex(currentFrame()); }
     bool frameHasAlphaAtIndex(size_t);
-    bool currentFrameHasAlpha() { return frameHasAlphaAtIndex(currentFrame()); }
+    virtual bool currentFrameHasAlpha() { return frameHasAlphaAtIndex(currentFrame()); }
 
 #if !ASSERT_DISABLED
-    bool notSolidColor()
+    virtual bool notSolidColor()
     {
         return size().width() != 1 || size().height() != 1 || frameCount() > 1;
     }

Source/WebCore/platform/graphics/Image.cpp

@@ -115,7 +115,7 @@ void Image::drawTiled(GraphicsContext* ctxt, const FloatRect& destRect, const Fl
 
     // See <https://webkit.org/b/59043>.
 #if !PLATFORM(WX)
-    ASSERT(!isBitmapImage() || static_cast<BitmapImage*>(this)->notSolidColor());
+    ASSERT(!isBitmapImage() || notSolidColor());
 #endif
 
     FloatSize intrinsicTileSize = size();

Source/WebCore/platform/graphics/Image.h

@@ -88,6 +88,7 @@ class Image : public RefCounted<Image> {
     static bool supportsType(const String&); 
 
     virtual bool isBitmapImage() const { return false; }
+    virtual bool currentFrameHasAlpha() { return false; }
 
     // Derived classes should override this if they can assure that 
     // the image contains only resources from its own security origin.
@@ -157,6 +158,10 @@ class Image : public RefCounted<Image> {
     virtual void drawPattern(GraphicsContext*, const FloatRect& srcRect, const AffineTransform& patternTransform,
                              const FloatPoint& phase, ColorSpace styleColorSpace, CompositeOperator, const FloatRect& destRect);
 
+#if !ASSERT_DISABLED
+    virtual bool notSolidColor() { return true; }
+#endif
+
 protected:
     Image(ImageObserver* = 0);
 

Source/WebCore/platform/graphics/skia/BitmapImageSingleFrameSkia.h

@@ -53,6 +53,8 @@ class BitmapImageSingleFrameSkia : public Image {
 
     virtual bool isBitmapImage() const { return true; }
 
+    virtual bool currentFrameHasAlpha() { return !m_nativeImage.isOpaque(); }
+
     virtual IntSize size() const
     {
         return IntSize(m_nativeImage.width(), m_nativeImage.height());
@@ -72,6 +74,13 @@ class BitmapImageSingleFrameSkia : public Image {
         return &m_nativeImage;
     }
 
+#if !ASSERT_DISABLED
+    virtual bool notSolidColor()
+    {
+        return m_nativeImage.width() != 1 || m_nativeImage.height() != 1;
+    }
+#endif
+
 protected:
     virtual void draw(GraphicsContext*, const FloatRect& dstRect, const FloatRect& srcRect, ColorSpace styleColorSpace, CompositeOperator);
 

Source/WebCore/rendering/RenderImage.cpp

@@ -408,13 +408,9 @@ bool RenderImage::backgroundIsObscured() const
 
     // Check for bitmap image with alpha.
     Image* image = m_imageResource->image().get();
-    if (!image || !image->isBitmapImage())
+    if (!image || !image->isBitmapImage() || image->currentFrameHasAlpha())
         return false;
 
-    BitmapImage* bitmapImage = static_cast<BitmapImage*>(image);
-    if (bitmapImage->currentFrameHasAlpha())
-        return false;
-
     return true;
 }