Merge 142759

Source/WebCore/svg/properties/SVGPathSegListPropertyTearOff.cpp

 /*
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 52 matching lines @@
 }
 
 SVGPathElement* SVGPathSegListPropertyTearOff::contextElement() const
 {
     SVGElement* contextElement = m_animatedProperty->contextElement();
     ASSERT(contextElement);
     ASSERT(contextElement->hasTagName(SVGNames::pathTag));
     return static_cast<SVGPathElement*>(contextElement);
 }
 
-void SVGPathSegListPropertyTearOff::processIncomingListItemValue(const ListItemType& newItem, unsigned* indexToModify)
+bool SVGPathSegListPropertyTearOff::processIncomingListItemValue(const ListItemType& newItem, unsigned* indexToModify)
 {
     SVGPathSegWithContext* newItemWithContext = static_cast<SVGPathSegWithContext*>(newItem.get());
     SVGAnimatedProperty* animatedPropertyOfItem = newItemWithContext->animatedProperty();
 
     // Alter the role, after calling animatedProperty(), as that may influence the returned animated property.
     newItemWithContext->setContextAndRole(contextElement(), m_pathSegRole);
 
     if (!animatedPropertyOfItem)
-        return;
+        return true;
 
     // newItem belongs to a SVGPathElement, but its associated SVGAnimatedProperty is not an animated list tear off.
     // (for example: "pathElement.pathSegList.appendItem(pathElement.createSVGPathSegClosepath())")
     if (!animatedPropertyOfItem->isAnimatedListTearOff())
-        return;
+        return true;
 
     // Spec: If newItem is already in a list, it is removed from its previous list before it is inserted into this list.
     // 'newItem' is already living in another list. If it's not our list, synchronize the other lists wrappers after the removal.
     bool livesInOtherList = animatedPropertyOfItem != m_animatedProperty;
-    int removedIndex = static_cast<SVGAnimatedPathSegListPropertyTearOff*>(animatedPropertyOfItem)->removeItemFromList(newItem.get(), livesInOtherList);
-    ASSERT(removedIndex != -1);
+    SVGAnimatedPathSegListPropertyTearOff* propertyTearOff = static_cast<SVGAnimatedPathSegListPropertyTearOff*>(animatedPropertyOfItem);
+    int indexToRemove = propertyTearOff->findItem(newItem.get());
+    ASSERT(indexToRemove != -1);
+
+    // Do not remove newItem if already in this list at the target index.
+    if (!livesInOtherList && indexToModify && static_cast<unsigned>(indexToRemove) == *indexToModify)
+        return false;
+
+    propertyTearOff->removeItemFromList(indexToRemove, livesInOtherList);
 
     if (!indexToModify)
-        return;
+        return true;
 
     // If the item lived in our list, adjust the insertion index.
     if (!livesInOtherList) {
         unsigned& index = *indexToModify;
         // Spec: If the item is already in this list, note that the index of the item to (replace|insert before) is before the removal of the item.
-        if (static_cast<unsigned>(removedIndex) < index)
+        if (static_cast<unsigned>(indexToRemove) < index)
             --index;
     }
+
+    return true;
 }
 
 }
 
 #endif // ENABLE(SVG)