[SVG] Reject hit-test queries when the element has a singular transform

Source/core/rendering/svg/SVGRenderSupport.cpp

 /*
  * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 309 matching lines @@
     SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(object);
     if (!resources)
         return true;
 
     if (RenderSVGResourceClipper* clipper = resources->clipper())
         return clipper->hitTestClipContent(object->objectBoundingBox(), point);
 
     return true;
 }
 
+bool SVGRenderSupport::transformToUserSpaceAndCheckClipping(RenderObject* object, const AffineTransform& localTransform, const FloatPoint& pointInParent, FloatPoint& localPoint)
+{
+    if (!localTransform.isInvertible())
+        return false;
+    localPoint = localTransform.inverse().mapPoint(pointInParent);
+    return pointInClippingArea(object, localPoint);
+}
+
 void SVGRenderSupport::applyStrokeStyleToContext(GraphicsContext* context, const RenderStyle* style, const RenderObject* object)
 {
     ASSERT(context);
     ASSERT(style);
     ASSERT(object);
     ASSERT(object->node());
     ASSERT(object->node()->isSVGElement());
 
     const SVGRenderStyle& svgStyle = style->svgStyle();
 
@@ skipping 45 matching lines @@
 }
 
 bool SVGRenderSupport::isRenderableTextNode(const RenderObject* object)
 {
     ASSERT(object->isText());
     // <br> is marked as text, but is not handled by the SVG rendering code-path.
     return object->isSVGInlineText() && !toRenderSVGInlineText(object)->hasEmptyText();
 }
 
 }