Use correct viewport for intrinsic size-less SVG images in <svg:image>

Source/core/rendering/svg/RenderSVGImage.cpp

 /*
  * Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007, 2008, 2009 Rob Buis <buis@kde.org>
  * Copyright (C) 2009 Google, Inc.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 19 matching lines @@
 #include "core/rendering/GraphicsContextAnnotator.h"
 #include "core/rendering/ImageQualityController.h"
 #include "core/rendering/PointerEventsHitRules.h"
 #include "core/rendering/RenderImageResource.h"
 #include "core/rendering/svg/RenderSVGResource.h"
 #include "core/rendering/svg/SVGRenderSupport.h"
 #include "core/rendering/svg/SVGRenderingContext.h"
 #include "core/rendering/svg/SVGResources.h"
 #include "core/rendering/svg/SVGResourcesCache.h"
 #include "core/svg/SVGImageElement.h"
+#include "platform/LengthFunctions.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 
 namespace blink {
 
 RenderSVGImage::RenderSVGImage(SVGImageElement* impl)
     : RenderSVGModelObject(impl)
     , m_needsBoundariesUpdate(true)
     , m_needsTransformUpdate(true)
     , m_imageResource(RenderImageResource::create())
 {
     m_imageResource->initialize(this);
 }
 
 RenderSVGImage::~RenderSVGImage()
 {
 }
 
 void RenderSVGImage::destroy()
 {
     ImageQualityController::remove(this);
     m_imageResource->shutdown();
     RenderSVGModelObject::destroy();
 }
 
+bool RenderSVGImage::forceNonUniformScaling(SVGImageElement* image) const
+{
+    // Images with preserveAspectRatio=none should force non-uniform
+    // scaling. This can be achieved by setting the image's container size to
+    // its intrinsic size. If the image does not have an intrinsic size - or
+    // the intrinsic size is degenerate - set the container size to the bounds
+    // as in pAR!=none cases.
+    // See: http://www.w3.org/TR/SVG/single-page.html, 7.8 The ‘preserveAspectRatio’ attribute.
+    if (image->preserveAspectRatio()->currentValue()->align() != SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_NONE)
+        return false;
+    ImageResource* cachedImage = m_imageResource->cachedImage();
+    if (!cachedImage)
+        return false;
+    Length intrinsicWidth;
+    Length intrinsicHeight;
+    FloatSize intrinsicRatio;
+    cachedImage->computeIntrinsicDimensions(intrinsicWidth, intrinsicHeight, intrinsicRatio);
+    if (!intrinsicWidth.isFixed() || !intrinsicHeight.isFixed())
+        return false;
+    // If the viewport defined by the referenced image is zero in either
+    // dimension, then SVGImage will have computed an intrinsic size of 300x150.
+    if (!floatValueForLength(intrinsicWidth, 0) || !floatValueForLength(intrinsicHeight, 0))
+        return false;
+    return true;
+}
+
 bool RenderSVGImage::updateImageViewport()
 {
     SVGImageElement* image = toSVGImageElement(element());
     FloatRect oldBoundaries = m_objectBoundingBox;
     bool updatedViewport = false;
 
     SVGLengthContext lengthContext(image);
     m_objectBoundingBox = FloatRect(image->x()->currentValue()->value(lengthContext), image->y()->currentValue()->value(lengthContext), image->width()->currentValue()->value(lengthContext), image->height()->currentValue()->value(lengthContext));
 
     bool boundsChanged = oldBoundaries != m_objectBoundingBox;
 
-    // Images with preserveAspectRatio=none should force non-uniform scaling. This can be achieved
-    // by setting the image's container size to its intrinsic size.
-    // See: http://www.w3.org/TR/SVG/single-page.html, 7.8 The ‘preserveAspectRatio’ attribute.
     IntSize newViewportSize;
-    if (image->preserveAspectRatio()->currentValue()->align() == SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_NONE) {
+    if (forceNonUniformScaling(image)) {
         LayoutSize intrinsicSize = m_imageResource->intrinsicSize(style()->effectiveZoom());
         if (intrinsicSize != m_imageResource->imageSize(style()->effectiveZoom())) {
             newViewportSize = roundedIntSize(intrinsicSize);
             updatedViewport = true;
         }
     } else if (boundsChanged) {
         newViewportSize = enclosingIntRect(m_objectBoundingBox).size();
         updatedViewport = true;
     }
     if (updatedViewport)
@@ skipping 139 matching lines @@
 
 void RenderSVGImage::addFocusRingRects(Vector<LayoutRect>& rects, const LayoutPoint&, const RenderLayerModelObject*) const
 {
     // this is called from paint() after the localTransform has already been applied
     LayoutRect contentRect = LayoutRect(paintInvalidationRectInLocalCoordinates());
     if (!contentRect.isEmpty())
         rects.append(contentRect);
 }
 
 } // namespace blink