Merge WebKit r55511

third_party/WebKit/WebCore/svg/SVGUseElement.cpp

 /*
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
                   2004, 2005, 2006, 2007 Rob Buis <buis@kde.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
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
@@ skipping 370 matching lines @@
 void SVGUseElement::buildPendingResource()
 {
     // If we're called the first time (during shadow tree root creation from RenderSVGShadowTreeRootContainer)
     // we either determine that our target is available or not - then we add ourselves to the pending resource list
     // Once the pending resource appears, it will call buildPendingResource(), so we're called a second time.
     String id = SVGURIReference::getTarget(href());
     Element* targetElement = document()->getElementById(id);
     ASSERT(!m_targetElementInstance);
 
     if (!targetElement) {
-        if (m_isPendingResource)
+        if (m_isPendingResource || id.isEmpty())
             return;
 
         m_isPendingResource = true;
         m_resourceId = id;
         document()->accessSVGExtensions()->addPendingResource(id, this);
         return;
     }
 
     if (m_isPendingResource) {
         ASSERT(!m_targetElementInstance);
         m_isPendingResource = false;    
         invalidateShadowTree();
     }
 }
 
 void SVGUseElement::buildShadowAndInstanceTree(SVGShadowTreeRootElement* shadowRoot)
 {
     String id = SVGURIReference::getTarget(href());
     Element* targetElement = document()->getElementById(id);
-    ASSERT(targetElement);
+    if (!targetElement) {
+        // The only time we should get here is when the use element has not been
+        // given a resource to target.
+        ASSERT(m_resourceId.isEmpty());
+        return;
+    }
 
     // Do not build the shadow/instance tree for <use> elements living in a shadow tree.
     // The will be expanded soon anyway - see expandUseElementsInShadowTree().
     Node* parent = parentNode();
     while (parent) {
         if (parent->isShadowNode())
             return;
 
         parent = parent->parentNode();
     }
@@ skipping 281 matching lines @@
     if (element->hasTagName(SVGNames::useTag)) {
         SVGUseElement* use = static_cast<SVGUseElement*>(element);
 
         String id = SVGURIReference::getTarget(use->href());
         Element* targetElement = document()->getElementById(id); 
         SVGElement* target = 0;
         if (targetElement && targetElement->isSVGElement())
             target = static_cast<SVGElement*>(targetElement);
 
         // Don't ASSERT(target) here, it may be "pending", too.
-        if (target) {
-            // Setup sub-shadow tree root node
-            RefPtr<SVGShadowTreeContainerElement> cloneParent = new SVGShadowTreeContainerElement(document());
+        // Setup sub-shadow tree root node
+        RefPtr<SVGShadowTreeContainerElement> cloneParent = new SVGShadowTreeContainerElement(document());
 
-            // Spec: In the generated content, the 'use' will be replaced by 'g', where all attributes from the
-            // 'use' element except for x, y, width, height and xlink:href are transferred to the generated 'g' element.
-            transferUseAttributesToReplacedElement(use, cloneParent.get());
+        // Spec: In the generated content, the 'use' will be replaced by 'g', where all attributes from the
+        // 'use' element except for x, y, width, height and xlink:href are transferred to the generated 'g' element.
+        transferUseAttributesToReplacedElement(use, cloneParent.get());
 
-            ExceptionCode ec = 0;
-
-            // For instance <use> on <foreignObject> (direct case).
-            if (isDisallowedElement(target)) {
-                // We still have to setup the <use> replacment (<g>). Otherwhise
-                // associateInstancesWithShadowTreeElements() makes wrong assumptions.
-                // Replace <use> with referenced content.
-                ASSERT(use->parentNode()); 
-                use->parentNode()->replaceChild(cloneParent.release(), use, ec);
-                ASSERT(!ec);
-                return;
-            }
-
+        ExceptionCode ec = 0;
+        if (target && !isDisallowedElement(target)) {
             RefPtr<Element> newChild = target->cloneElementWithChildren();
 
             // We don't walk the target tree element-by-element, and clone each element,
             // but instead use cloneElementWithChildren(). This is an optimization for the common
             // case where <use> doesn't contain disallowed elements (ie. <foreignObject>).
             // Though if there are disallowed elements in the subtree, we have to remove them.
             // For instance: <use> on <g> containing <foreignObject> (indirect case).
             if (subtreeContainsDisallowedElement(newChild.get()))
                 removeDisallowedElementsFromSubtree(newChild.get());
 
             SVGElement* newChildPtr = 0;
             if (newChild->isSVGElement())
                 newChildPtr = static_cast<SVGElement*>(newChild.get());
             ASSERT(newChildPtr);
 
             cloneParent->appendChild(newChild.release(), ec);
             ASSERT(!ec);
+        }
 
-            // Replace <use> with referenced content.
-            ASSERT(use->parentNode()); 
-            use->parentNode()->replaceChild(cloneParent.release(), use, ec);
-            ASSERT(!ec);
+        // Replace <use> with referenced content.
+        ASSERT(use->parentNode()); 
+        use->parentNode()->replaceChild(cloneParent.release(), use, ec);
+        ASSERT(!ec);
 
-            // Immediately stop here, and restart expanding.
-            expandUseElementsInShadowTree(shadowRoot, shadowRoot);
-            return;
-        }
+        // Immediately stop here, and restart expanding.
+        expandUseElementsInShadowTree(shadowRoot, shadowRoot);
+        return;
     }
 
     for (RefPtr<Node> child = element->firstChild(); child; child = child->nextSibling())
         expandUseElementsInShadowTree(shadowRoot, child.get());
 }
 
 void SVGUseElement::expandSymbolElementsInShadowTree(SVGShadowTreeRootElement* shadowRoot, Node* element)
 {
     if (element->hasTagName(SVGNames::symbolTag)) {
         // Spec: The referenced 'symbol' and its contents are deep-cloned into the generated tree,
@@ skipping 170 matching lines @@
 }
 
 bool SVGUseElement::hasRelativeValues() const
 {
     return x().isRelative() || y().isRelative() || width().isRelative() || height().isRelative();
 }
 
 }
 
 #endif // ENABLE(SVG)