Gradients should restrict possible content

Source/core/rendering/svg/RenderSVGResourceGradient.cpp

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 108 matching lines @@
     updateGraphicsContext(context, style, *object, resourceMode);
     return true;
 }
 
 void RenderSVGResourceGradient::postApplyResource(GraphicsContext* context)
 {
     ASSERT(context);
     context->restore();
 }
 
+bool RenderSVGResourceGradient::isChildAllowed(RenderObject* child, RenderStyle*) const
+{
+    if (child->isSVGGradientStop())
+        return true;
+
+    if (!child->isSVGResourceContainer())
+        return false;
+
+    RenderSVGResourceContainer* resource = toRenderSVGResourceContainer(child);
+    return resource->resourceType() == PatternResourceType
+        || resource->resourceType() == LinearGradientResourceType
+        || resource->resourceType() == RadialGradientResourceType;
+}
+
 void RenderSVGResourceGradient::addStops(GradientData* gradientData, const Vector<Gradient::ColorStop>& stops) const
 {
     ASSERT(gradientData->gradient);
 
     const Vector<Gradient::ColorStop>::const_iterator end = stops.end();
     for (Vector<Gradient::ColorStop>::const_iterator it = stops.begin(); it != end; ++it)
         gradientData->gradient->addColorStop(*it);
 }
 
 GradientSpreadMethod RenderSVGResourceGradient::platformSpreadMethodFromSVGType(SVGSpreadMethodType method) const
 {
     switch (method) {
     case SVGSpreadMethodUnknown:
     case SVGSpreadMethodPad:
         return SpreadMethodPad;
     case SVGSpreadMethodReflect:
         return SpreadMethodReflect;
     case SVGSpreadMethodRepeat:
         return SpreadMethodRepeat;
     }
 
     ASSERT_NOT_REACHED();
     return SpreadMethodPad;
 }
 
 }