--- a/content/base/src/nsGenericElement.cpp
+++ b/content/base/src/nsGenericElement.cpp
@@ -2894,16 +2894,24 @@ nsGenericElement::GetAttributeNodeNS(con
                                      const nsAString& aLocalName,
                                      nsIDOMAttr** aReturn)
 {
   NS_ENSURE_ARG_POINTER(aReturn);
   *aReturn = nsnull;
 
   OwnerDoc()->WarnOnceAbout(nsIDocument::eGetAttributeNodeNS);
 
+  return GetAttributeNodeNSInternal(aNamespaceURI, aLocalName, aReturn);
+}
+
+nsresult
+nsGenericElement::GetAttributeNodeNSInternal(const nsAString& aNamespaceURI,
+                                             const nsAString& aLocalName,
+                                             nsIDOMAttr** aReturn)
+{
   nsCOMPtr<nsIDOMNamedNodeMap> map;
   nsresult rv = GetAttributes(getter_AddRefs(map));
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsCOMPtr<nsIDOMNode> node;
   rv = map->GetNamedItemNS(aNamespaceURI, aLocalName, getter_AddRefs(node));
 
   if (NS_SUCCEEDED(rv) && node) {
@@ -5201,18 +5209,18 @@ nsGenericElement::SetAttrAndNotify(PRInt
   }
 
   if (aFireMutation) {
     nsMutationEvent mutation(true, NS_MUTATION_ATTRMODIFIED);
 
     nsCOMPtr<nsIDOMAttr> attrNode;
     nsAutoString ns;
     nsContentUtils::NameSpaceManager()->GetNameSpaceURI(aNamespaceID, ns);
-    GetAttributeNodeNS(ns, nsDependentAtomString(aName),
-                       getter_AddRefs(attrNode));
+    GetAttributeNodeNSInternal(ns, nsDependentAtomString(aName),
+                               getter_AddRefs(attrNode));
     mutation.mRelatedNode = attrNode;
 
     mutation.mAttrName = aName;
     nsAutoString newValue;
     GetAttr(aNamespaceID, aName, newValue);
     if (!newValue.IsEmpty()) {
       mutation.mNewAttrValue = do_GetAtom(newValue);
     }
@@ -5381,18 +5389,18 @@ nsGenericElement::UnsetAttr(PRInt32 aNam
                                          NS_EVENT_BITS_MUTATION_ATTRMODIFIED,
                                          this);
 
   // Grab the attr node if needed before we remove it from the attr map
   nsCOMPtr<nsIDOMAttr> attrNode;
   if (hasMutationListeners) {
     nsAutoString ns;
     nsContentUtils::NameSpaceManager()->GetNameSpaceURI(aNameSpaceID, ns);
-    GetAttributeNodeNS(ns, nsDependentAtomString(aName),
-                       getter_AddRefs(attrNode));
+    GetAttributeNodeNSInternal(ns, nsDependentAtomString(aName),
+                               getter_AddRefs(attrNode));
   }
 
   // Clear binding to nsIDOMNamedNodeMap
   nsDOMSlots *slots = GetExistingDOMSlots();
   if (slots && slots->mAttributeMap) {
     slots->mAttributeMap->DropAttribute(aNameSpaceID, aName);
   }
 

--- a/content/base/src/nsGenericElement.h
+++ b/content/base/src/nsGenericElement.h
@@ -789,16 +789,20 @@ protected:
 
   nsIFrame* GetStyledFrame();
 
   virtual mozilla::dom::Element* GetNameSpaceElement()
   {
     return this;
   }
 
+  nsresult GetAttributeNodeNSInternal(const nsAString& aNamespaceURI,
+                                      const nsAString& aLocalName,
+                                      nsIDOMAttr** aReturn);
+
 public:
   // Because of a bug in MS C++ compiler nsDOMSlots must be declared public,
   // otherwise nsXULElement::nsXULSlots doesn't compile.
   /**
    * There are a set of DOM- and scripting-specific instance variables
    * that may only be instantiated when a content object is accessed
    * through the DOM. Rather than burn actual slots in the content
    * objects for each of these instance variables, we put them off

--- a/content/xul/content/src/nsXULElement.cpp
+++ b/content/xul/content/src/nsXULElement.cpp
@@ -1363,17 +1363,18 @@ nsXULElement::UnsetAttr(PRInt32 aNameSpa
     bool hasMutationListeners = aNotify &&
         nsContentUtils::HasMutationListeners(this,
             NS_EVENT_BITS_MUTATION_ATTRMODIFIED, this);
 
     nsCOMPtr<nsIDOMAttr> attrNode;
     if (hasMutationListeners) {
         nsAutoString ns;
         nsContentUtils::NameSpaceManager()->GetNameSpaceURI(aNameSpaceID, ns);
-        GetAttributeNodeNS(ns, nsDependentAtomString(aName), getter_AddRefs(attrNode));
+        GetAttributeNodeNSInternal(ns, nsDependentAtomString(aName),
+                                   getter_AddRefs(attrNode));
     }
 
     nsDOMSlots *slots = GetExistingDOMSlots();
     if (slots && slots->mAttributeMap) {
       slots->mAttributeMap->DropAttribute(aNameSpaceID, aName);
     }
 
     // The id-handling code, and in the future possibly other code, need to