Merge 109299

Source/WebCore/svg/SVGUseElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. 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 403 matching lines @@
 
     ++depth;
 
     for (SVGElementInstance* instance = targetInstance->firstChild(); instance; instance = instance->nextSibling())
         dumpInstanceTree(depth, text, instance);
 
     --depth;
 }
 #endif
 
-static bool isDisallowedElement(Node* element)
+static bool isDisallowedElement(Node* node)
 {
-    // <foreignObject> should never be contained in a <use> tree. Too dangerous side effects possible.
-    if (element->hasTagName(SVGNames::foreignObjectTag))
+    // Spec: "Any 'svg', 'symbol', 'g', graphics element or other 'use' is potentially a template object that can be re-used
+    // (i.e., "instanced") in the SVG document via a 'use' element."
+    // "Graphics Element" is defined as 'circle', 'ellipse', 'image', 'line', 'path', 'polygon', 'polyline', 'rect', 'text'
+    // Excluded are anything that is used by reference or that only make sense to appear once in a document.
+    // We must also allow the shadow roots of other use elements and text.
+    if (node->isTextNode())
+        return false;
+
+    if (!node->isSVGElement())
         return true;
-    if (SVGSMILElement::isSMILElement(element))
-        return true;
-    return false;
+
+    SVGElement* element = static_cast<SVGElement*>(node);
+
+    DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, allowedElementTags, ());
+    if (allowedElementTags.isEmpty()) {
+        allowedElementTags.add(SVGNames::aTag);
+        allowedElementTags.add(SVGNames::circleTag);
+        allowedElementTags.add(SVGNames::defsTag);
+        allowedElementTags.add(SVGNames::descTag);
+        allowedElementTags.add(SVGNames::ellipseTag);
+        allowedElementTags.add(SVGNames::gTag);
+        allowedElementTags.add(SVGNames::imageTag);
+        allowedElementTags.add(SVGNames::lineTag);
+        allowedElementTags.add(SVGNames::metadataTag);
+        allowedElementTags.add(SVGNames::pathTag);
+        allowedElementTags.add(SVGNames::polygonTag);
+        allowedElementTags.add(SVGNames::polylineTag);
+        allowedElementTags.add(SVGNames::rectTag);
+        allowedElementTags.add(SVGNames::svgTag);
+        allowedElementTags.add(SVGNames::switchTag);
+        allowedElementTags.add(SVGNames::symbolTag);
+        allowedElementTags.add(SVGNames::textTag);
+        allowedElementTags.add(SVGNames::textPathTag);
+        allowedElementTags.add(SVGNames::titleTag);
+        allowedElementTags.add(SVGNames::trefTag);
+        allowedElementTags.add(SVGNames::tspanTag);
+        allowedElementTags.add(SVGNames::useTag);
+    }
+    return !allowedElementTags.contains<QualifiedName, SVGAttributeHashTranslator>(element->tagQName());
 }
 
 static bool subtreeContainsDisallowedElement(Node* start)
 {
     if (isDisallowedElement(start))
         return true;
 
     for (Node* cur = start->firstChild(); cur; cur = cur->nextSibling()) {
         if (subtreeContainsDisallowedElement(cur))
             return true;
@@ skipping 605 matching lines @@
     SVGElement* element = m_targetElementInstance->correspondingElement();
     if (!element || !element->isStyled())
         return false;
 
     return static_cast<SVGStyledElement*>(element)->hasRelativeLengths();
 }
 
 }
 
 #endif // ENABLE(SVG)