Bug 453858. Get rid of some XPCOM-ness in nsArraySH::GetItemAt. r+sr=jst

content/base/public/Makefile.in

@@ -59,6 +59,7 @@ nsIMutationObserver.h \
 nsINameSpaceManager.h \
 nsINode.h \
 nsINodeInfo.h \
+nsINodeList.h \
 nsIRange.h \
 nsIRangeUtils.h \
 nsIScriptElement.h \

content/base/public/nsINodeList.h

@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is Mozilla.com.
+ * Portions created by the Initial Developer are Copyright (C) 2008
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *         Boris Zbarsky <bzbarsky@mit.edu> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsINodeList_h___
+#define nsINodeList_h___
+
+class nsINode;
+
+// IID for the nsINodeList interface
+#define NS_INODELIST_IID \
+{ 0x06a6639a, 0x2d47, 0x4551, \
+ { 0x94, 0xef, 0x93, 0xb8, 0xe1, 0x09, 0x3a, 0xb3 } }
+
+
+/**
+ * An internal interface that allows QI-less getting of nodes from node lists
+ */
+class nsINodeList : public nsISupports {
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_INODELIST_IID)
+
+  /**
+   * Get the node at the index.  Returns null if the index is out of bounds
+   */
+  virtual nsINode* GetNodeAt(PRUint32 aIndex) = 0;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsINodeList, NS_INODELIST_IID)
+
+#endif /* nsINodeList_h___ */

content/base/src/nsContentList.cpp

@@ -88,6 +88,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 // QueryInterface implementation for nsBaseContentList
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsBaseContentList)
+  NS_INTERFACE_MAP_ENTRY(nsINodeList)
   NS_INTERFACE_MAP_ENTRY(nsIDOMNodeList)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMNodeList)
   NS_INTERFACE_MAP_ENTRY_CONTENT_CLASSINFO(NodeList)
@@ -109,7 +110,7 @@ nsBaseContentList::GetLength(PRUint32* aLength)
 NS_IMETHODIMP
 nsBaseContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
 {
-  nsISupports *tmp = mElements.SafeObjectAt(aIndex);
+  nsISupports *tmp = GetNodeAt(aIndex);
 
   if (!tmp) {
     *aReturn = nsnull;
@@ -120,6 +121,12 @@ nsBaseContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
   return CallQueryInterface(tmp, aReturn);
 }
 
+nsINode*
+nsBaseContentList::GetNodeAt(PRUint32 aIndex)
+{
+  return mElements.SafeObjectAt(aIndex);
+}
+
 void
 nsBaseContentList::AppendElement(nsIContent *aContent)
 {
@@ -467,10 +474,10 @@ nsContentList::GetLength(PRUint32* aLength)
 NS_IMETHODIMP
 nsContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
 {
-  nsIContent *content = Item(aIndex, PR_TRUE);
+  nsINode* node = GetNodeAt(aIndex);
 
-  if (content) {
-    return CallQueryInterface(content, aReturn);
+  if (node) {
+    return CallQueryInterface(node, aReturn);
   }
 
   *aReturn = nsnull;
@@ -492,6 +499,12 @@ nsContentList::NamedItem(const nsAString& aName, nsIDOMNode** aReturn)
   return NS_OK;
 }
 
+nsINode*
+nsContentList::GetNodeAt(PRUint32 aIndex)
+{
+  return Item(aIndex, PR_TRUE);
+}
+
 void
 nsContentList::AttributeChanged(nsIDocument *aDocument, nsIContent* aContent,
                                 PRInt32 aNameSpaceID, nsIAtom* aAttribute,

content/base/src/nsContentList.h

@@ -49,6 +49,7 @@
 #include "nsString.h"
 #include "nsIDOMHTMLCollection.h"
 #include "nsIDOMNodeList.h"
+#include "nsINodeList.h"
 #include "nsStubMutationObserver.h"
 #include "nsIAtom.h"
 #include "nsINameSpaceManager.h"
@@ -73,7 +74,8 @@ class nsIDocument;
 class nsIDOMHTMLFormElement;
 
 
-class nsBaseContentList : public nsIDOMNodeList
+class nsBaseContentList : public nsIDOMNodeList,
+                          public nsINodeList
 {
 public:
   nsBaseContentList();
@@ -83,7 +85,11 @@ public:
 
   // nsIDOMNodeList
   NS_DECL_NSIDOMNODELIST
-  NS_DECL_CYCLE_COLLECTION_CLASS(nsBaseContentList)
+
+  // nsINodeList
+  virtual nsINode* GetNodeAt(PRUint32 aIndex);
+  
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsBaseContentList, nsIDOMNodeList)
 
   void AppendElement(nsIContent *aContent);
   void RemoveElement(nsIContent *aContent);
@@ -232,6 +238,8 @@ public:
 
   // nsBaseContentList overrides
   virtual PRInt32 IndexOf(nsIContent *aContent, PRBool aDoFlush);
+  virtual nsINode* GetNodeAt(PRUint32 aIndex);
+  
 
   // nsContentList public methods
   NS_HIDDEN_(nsISupports*) GetParentObject();

content/base/src/nsDocument.cpp

@@ -304,7 +304,7 @@ nsIdentifierMapEntry::Traverse(nsCycleCollectionTraversalCallback* aCallback)
   if (mNameContentList != NAME_NOT_VALID) {
     NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                        "mIdentifierMap mNameContentList");
-    aCallback->NoteXPCOMChild(mNameContentList);
+    aCallback->NoteXPCOMChild(static_cast<nsIDOMNodeList*>(mNameContentList));
   }
 
   NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback, "mIdentifierMap mDocAllList");

content/base/src/nsGenericDOMNodeList.cpp

@@ -58,9 +58,20 @@ NS_IMPL_RELEASE(nsGenericDOMNodeList)
 
 // QueryInterface implementation for nsGenericDOMNodeList
 NS_INTERFACE_MAP_BEGIN(nsGenericDOMNodeList)
+  NS_INTERFACE_MAP_ENTRY(nsINodeList)
   NS_INTERFACE_MAP_ENTRY(nsIDOMNodeList)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMNodeList)
   NS_INTERFACE_MAP_ENTRY_CONTENT_CLASSINFO(NodeList)
 NS_INTERFACE_MAP_END
 
+NS_IMETHODIMP
+nsGenericDOMNodeList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
+{
+  nsINode* node = GetNodeAt(aIndex);
+  if (!node) {
+    *aReturn = nsnull;
+    return NS_OK;
+  }
 
+  return CallQueryInterface(node, aReturn);
+}

content/base/src/nsGenericDOMNodeList.h

@@ -36,17 +36,22 @@
  * ***** END LICENSE BLOCK ***** */
 
 /*
- * A base class for simple DOM NodeLists which implements nsISupports
- * and expects subclasess to implement GetLength() and Item()
+ * A base class for simple DOM NodeLists which implements nsISupports and Item()
+ * and expects subclasess to implement GetLength() and GetNodeAt()
  */
 
+// XXXbz we don't use this for much... should we be using it more, or
+// just nix it?
+
 #ifndef nsGenericDOMNodeList_h__
 #define nsGenericDOMNodeList_h__
 
 #include "nsISupports.h"
 #include "nsIDOMNodeList.h"
+#include "nsINodeList.h"
 
-class nsGenericDOMNodeList : public nsIDOMNodeList 
+class nsGenericDOMNodeList : public nsIDOMNodeList,
+                             public nsINodeList
 {
 public:
   nsGenericDOMNodeList();
@@ -54,10 +59,14 @@ public:
 
   NS_DECL_ISUPPORTS
 
+  NS_IMETHOD    Item(PRUint32 aIndex, nsIDOMNode** aReturn);
+
   // The following need to be defined in the subclass
   // nsIDOMNodeList interface
   NS_IMETHOD    GetLength(PRUint32* aLength)=0;
-  NS_IMETHOD    Item(PRUint32 aIndex, nsIDOMNode** aReturn)=0;
+
+  // nsINodeList interface
+  virtual nsINode* GetNodeAt(PRUint32 aIndex) = 0;
 };
 
 #endif // nsGenericDOMNodeList_h__

content/base/src/nsGenericElement.cpp

@@ -469,19 +469,14 @@ nsChildContentList::GetLength(PRUint32* aLength)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsChildContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
+nsINode*
+nsChildContentList::GetNodeAt(PRUint32 aIndex)
 {
   if (mNode) {
-    nsIContent *content = mNode->GetChildAt(aIndex);
-    if (content) {
-      return CallQueryInterface(content, aReturn);
-    }
+    return mNode->GetChildAt(aIndex);
   }
 
-  *aReturn = nsnull;
-
-  return NS_OK;
+  return nsnull;
 }
 
 //----------------------------------------------------------------------
@@ -1664,43 +1659,6 @@ nsNodeSelectorTearoff::QuerySelectorAll(const nsAString& aSelector,
   return nsGenericElement::doQuerySelectorAll(mContent, aSelector, aReturn);
 }
 
-//----------------------------------------------------------------------
-
-NS_IMPL_CYCLE_COLLECTION_CLASS(nsStaticContentList)
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsStaticContentList)
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMARRAY(mList)
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
-NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsStaticContentList)
-NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMARRAY(mList)
-NS_IMPL_CYCLE_COLLECTION_UNLINK_END
-
-NS_IMPL_CYCLE_COLLECTING_ADDREF(nsStaticContentList)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(nsStaticContentList)
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsStaticContentList)
-  NS_INTERFACE_MAP_ENTRY(nsIDOMNodeList)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
-  NS_INTERFACE_MAP_ENTRY_CONTENT_CLASSINFO(NodeList)
-NS_INTERFACE_MAP_END
-
-NS_IMETHODIMP
-nsStaticContentList::GetLength(PRUint32* aLength)
-{
-  *aLength = mList.Count();
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsStaticContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
-{
-  nsIContent* c = mList.SafeObjectAt(aIndex);
-  if (!c) {
-    *aReturn = nsnull;
-    return NS_OK;
-  }
-
-  return CallQueryInterface(c, aReturn);
-}
-
 //----------------------------------------------------------------------
 nsGenericElement::nsDOMSlots::nsDOMSlots(PtrBits aFlags)
   : nsINode::nsSlots(aFlags),
@@ -5274,7 +5232,7 @@ AppendAllMatchingElements(nsIContent* aMatchingElement,
                           void* aClosure)
 {
   NS_PRECONDITION(aMatchingElement && aClosure, "How did that happen?");
-  static_cast<nsStaticContentList*>(aClosure)->AppendContent(aMatchingElement);
+  static_cast<nsBaseContentList*>(aClosure)->AppendElement(aMatchingElement);
   return PR_TRUE;
 }
 
@@ -5286,7 +5244,7 @@ nsGenericElement::doQuerySelectorAll(nsINode* aRoot,
 {
   NS_PRECONDITION(aReturn, "Null out param?");
 
-  nsStaticContentList* contentList = new nsStaticContentList();
+  nsBaseContentList* contentList = new nsBaseContentList();
   NS_ENSURE_TRUE(contentList, NS_ERROR_OUT_OF_MEMORY);
   NS_ADDREF(*aReturn = contentList);
   

content/base/src/nsGenericElement.h

@@ -101,7 +101,10 @@ public:
   virtual ~nsChildContentList();
 
   // nsIDOMNodeList interface
-  NS_DECL_NSIDOMNODELIST
+  NS_IMETHOD GetLength(PRUint32* aLength);
+
+  // nsINodeList interface
+  virtual nsINode* GetNodeAt(PRUint32 aIndex);  
   
   void DropReference()
   {
@@ -295,28 +298,6 @@ private:
   nsCOMPtr<nsIContent> mContent;
 };
 
-/**
- * A static NodeList class, which just holds a COMArray of nodes
- */
-class nsStaticContentList : public nsIDOMNodeList {
-public:
-  nsStaticContentList() {}
-
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_NSIDOMNODELIST
-
-  NS_DECL_CYCLE_COLLECTION_CLASS(nsStaticContentList)
-
-  PRBool AppendContent(nsIContent* aContent) {
-    return mList.AppendObject(aContent);
-  }
-
-private:
-  ~nsStaticContentList() {}
-  
-  nsCOMArray<nsIContent> mList;
-};
-
 // Forward declare to allow being a friend
 class nsNSElementTearoff;
 

content/html/content/src/nsHTMLFormElement.cpp

@@ -350,7 +350,8 @@ PRBool nsHTMLFormElement::gPasswordManagerInitialized = PR_FALSE;
 
 // nsFormControlList
 class nsFormControlList : public nsIDOMNSHTMLFormControlList,
-                          public nsIDOMHTMLCollection
+                          public nsIDOMHTMLCollection,
+                          public nsINodeList
 {
 public:
   nsFormControlList(nsHTMLFormElement* aForm);
@@ -368,6 +369,9 @@ public:
   // nsIDOMNSHTMLFormControlList interface
   NS_DECL_NSIDOMNSHTMLFORMCONTROLLIST
 
+  // nsINodeList interface
+  virtual nsINode* GetNodeAt(PRUint32 aIndex);  
+
   nsresult AddElementToTable(nsIFormControl* aChild,
                              const nsAString& aName);
   nsresult RemoveElementFromTable(nsIFormControl* aChild,
@@ -2114,8 +2118,9 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 // XPConnect interface list for nsFormControlList
 NS_INTERFACE_TABLE_HEAD(nsFormControlList)
-  NS_INTERFACE_TABLE2(nsFormControlList,
+  NS_INTERFACE_TABLE3(nsFormControlList,
                       nsIDOMHTMLCollection,
+                      nsINodeList,
                       nsIDOMNSHTMLFormControlList)
   NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(nsFormControlList)
   NS_INTERFACE_MAP_ENTRY_CONTENT_CLASSINFO(HTMLFormControlCollection)
@@ -2141,16 +2146,15 @@ nsFormControlList::GetLength(PRUint32* aLength)
 NS_IMETHODIMP
 nsFormControlList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
 {
-  FlushPendingNotifications();
-
-  if (aIndex < mElements.Length()) {
-    return CallQueryInterface(mElements[aIndex], aReturn);
-  }
-
+  nsINode* node = GetNodeAt(aIndex);
+  if (!node) {
     *aReturn = nsnull;
     return NS_OK;
   }
 
+  return CallQueryInterface(node, aReturn);
+}
+
 NS_IMETHODIMP 
 nsFormControlList::NamedItem(const nsAString& aName,
                              nsIDOMNode** aReturn)
@@ -2194,6 +2198,18 @@ nsFormControlList::NamedItem(const nsAString& aName,
   return NS_OK;
 }
 
+nsINode*
+nsFormControlList::GetNodeAt(PRUint32 aIndex)
+{
+  FlushPendingNotifications();
+
+  if (aIndex < mElements.Length()) {
+    mElements[aIndex];
+  }
+
+  return nsnull;
+}
+
 void
 nsFormControlList::NamedItemInternal(const nsAString& aName,
                                      PRBool aFlushContent,
@@ -2246,7 +2262,8 @@ nsFormControlList::AddElementToTable(nsIFormControl* aChild,
       // Add the new child too
       list->AppendElement(newChild);
 
-      nsCOMPtr<nsISupports> listSupports = do_QueryInterface(list);
+      nsCOMPtr<nsISupports> listSupports =
+        do_QueryInterface(static_cast<nsIDOMNodeList*>(list));
 
       // Replace the element with the list.
       NS_ENSURE_TRUE(mNameLookupTable.Put(aName, listSupports),

content/html/content/src/nsHTMLMapElement.cpp

@@ -94,7 +94,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(nsHTMLMapElement)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHTMLMapElement,
                                                   nsGenericHTMLElement)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mAreas,
-                                                       nsBaseContentList)
+                                                       nsIDOMNodeList)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_ADDREF_INHERITED(nsHTMLMapElement, nsGenericElement) 

content/html/content/src/nsHTMLTableElement.cpp

@@ -144,7 +144,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(TableRowsCollection)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_0(TableRowsCollection)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(TableRowsCollection)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mOrphanRows,
-                                                       nsBaseContentList)
+                                                       nsIDOMNodeList)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(TableRowsCollection)
@@ -354,7 +354,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(nsHTMLTableElement)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHTMLTableElement,
                                                   nsGenericHTMLElement)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mTBodies,
-                                                       nsBaseContentList)
+                                                       nsIDOMNodeList)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mRows)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 

content/html/content/src/nsHTMLTableRowElement.cpp

@@ -101,7 +101,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(nsHTMLTableRowElement)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHTMLTableRowElement,
                                                   nsGenericHTMLElement)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mCells,
-                                                       nsBaseContentList)
+                                                       nsIDOMNodeList)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_ADDREF_INHERITED(nsHTMLTableRowElement, nsGenericElement) 

content/html/content/src/nsHTMLTableSectionElement.cpp

@@ -99,7 +99,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(nsHTMLTableSectionElement)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHTMLTableSectionElement,
                                                   nsGenericHTMLElement)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mRows,
-                                                       nsBaseContentList)
+                                                       nsIDOMNodeList)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_ADDREF_INHERITED(nsHTMLTableSectionElement, nsGenericElement) 

content/xbl/src/nsBindingManager.cpp

@@ -92,17 +92,21 @@
   { 0xa29df1f8, 0xaeca, 0x4356, \
     { 0xa8, 0xc2, 0xa7, 0x24, 0xa2, 0x11, 0x73, 0xac } }
 
-class nsAnonymousContentList : public nsIDOMNodeList
+class nsAnonymousContentList : public nsIDOMNodeList,
+                               public nsINodeList
 {
 public:
   nsAnonymousContentList(nsInsertionPointList* aElements);
   virtual ~nsAnonymousContentList();
 
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_CLASS(nsAnonymousContentList)
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsAnonymousContentList, nsIDOMNodeList)
   // nsIDOMNodeList interface
   NS_DECL_NSIDOMNODELIST
 
+  // nsINodeList interface
+  virtual nsINode* GetNodeAt(PRUint32 aIndex);
+
   PRInt32 GetInsertionPointCount() { return mElements->Length(); }
 
   nsXBLInsertionPoint* GetInsertionPointAt(PRInt32 i) { return static_cast<nsXBLInsertionPoint*>(mElements->ElementAt(i)); }
@@ -136,9 +140,12 @@ NS_IMPL_CYCLE_COLLECTING_ADDREF(nsAnonymousContentList)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(nsAnonymousContentList)
 
 NS_INTERFACE_MAP_BEGIN(nsAnonymousContentList)
+  NS_INTERFACE_MAP_ENTRY(nsINodeList)
   NS_INTERFACE_MAP_ENTRY(nsIDOMNodeList)
-  NS_INTERFACE_MAP_ENTRY(nsAnonymousContentList)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  if (aIID.Equals(NS_GET_IID(nsAnonymousContentList)))
+    foundInterface = static_cast<nsIDOMNodeList*>(this);
+  else
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMNodeList)
   NS_INTERFACE_MAP_ENTRY_CONTENT_CLASSINFO(NodeList)
   NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(nsAnonymousContentList)
 NS_INTERFACE_MAP_END
@@ -172,6 +179,16 @@ nsAnonymousContentList::GetLength(PRUint32* aLength)
 
 NS_IMETHODIMP    
 nsAnonymousContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
+{
+  nsINode* item = GetNodeAt(aIndex);
+  if (!item)
+    return NS_ERROR_FAILURE;
+
+  return CallQueryInterface(item, aReturn);    
+}
+
+nsINode*
+nsAnonymousContentList::GetNodeAt(PRUint32 aIndex)
 {
   PRInt32 cnt = mElements->Length();
   PRUint32 pointCount = 0;
@@ -183,14 +200,11 @@ nsAnonymousContentList::Item(PRUint32 aIndex, nsIDOMNode** aReturn)
     pointCount = point->ChildCount();
 
     if (aIndex < pointCount) {
-      nsCOMPtr<nsIContent> result = point->ChildAt(aIndex);
-      if (result)
-        return CallQueryInterface(result, aReturn);
-      return NS_ERROR_FAILURE;
+      return point->ChildAt(aIndex);
     }
   }
 
-  return NS_ERROR_FAILURE;
+  return nsnull;
 }
 
 //
@@ -444,7 +458,10 @@ PR_CALLBACK RemoveInsertionParentCB(PLDHashTable* aTable, PLDHashEntryHdr* aEntr
 static void
 RemoveInsertionParentForNodeList(nsIDOMNodeList* aList, nsIContent* aParent)
 {
-  nsCOMPtr<nsAnonymousContentList> list = do_QueryInterface(aList);
+  nsAnonymousContentList* list = nsnull;
+  if (aList) {
+    CallQueryInterface(aList, &list);
+  }
   if (list) {
     PRInt32 count = list->GetInsertionPointCount();
     for (PRInt32 i = 0; i < count; ++i) {
@@ -456,6 +473,7 @@ RemoveInsertionParentForNodeList(nsIDOMNodeList* aList, nsIContent* aParent)
 #endif
       currPoint->ClearInsertionParent();
     }
+    NS_RELEASE(list);
   }
 }
 
@@ -1509,8 +1527,9 @@ nsBindingManager::ContentRemoved(nsIDocument* aDocument,
     // aChild from the pseudo insertion point it's in.
     if (mContentListTable.ops) {
       nsAnonymousContentList* insertionPointList =
-        static_cast<nsAnonymousContentList*>(LookupObject(mContentListTable,
-                                                          aContainer));
+        static_cast<nsAnonymousContentList*>(
+          static_cast<nsIDOMNodeList*>(LookupObject(mContentListTable,
+                                                    aContainer)));
       if (insertionPointList) {
         RemoveChildFromInsertionPoint(insertionPointList, aChild, PR_TRUE);
       }

content/xbl/src/nsXBLInsertionPoint.cpp

@@ -79,35 +79,28 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(nsXBLInsertionPoint, AddRef)
 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(nsXBLInsertionPoint, Release)
 
-already_AddRefed<nsIContent>
+nsIContent*
 nsXBLInsertionPoint::GetInsertionParent()
 {
-  NS_IF_ADDREF(mParentElement);
   return mParentElement;
 }
 
-already_AddRefed<nsIContent>
+nsIContent*
 nsXBLInsertionPoint::GetDefaultContent()
 {
-  nsIContent* defaultContent = mDefaultContent;
-  NS_IF_ADDREF(defaultContent);
-  return defaultContent;
+  return mDefaultContent;
 }
 
-already_AddRefed<nsIContent>
+nsIContent*
 nsXBLInsertionPoint::GetDefaultContentTemplate()
 {
-  nsIContent* defaultContent = mDefaultContentTemplate;
-  NS_IF_ADDREF(defaultContent);
-  return defaultContent;
+  return mDefaultContentTemplate;
 }
 
-already_AddRefed<nsIContent>
+nsIContent*
 nsXBLInsertionPoint::ChildAt(PRUint32 aIndex)
 {
-  nsIContent* result = mElements.ObjectAt(aIndex);
-  NS_IF_ADDREF(result);
-  return result;
+  return mElements.ObjectAt(aIndex);
 }
 
 PRBool

content/xbl/src/nsXBLInsertionPoint.h

@@ -62,16 +62,16 @@ public:
 
   NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(nsXBLInsertionPoint)
 
-  already_AddRefed<nsIContent> GetInsertionParent();
+  nsIContent* GetInsertionParent();
   void ClearInsertionParent() { mParentElement = nsnull; }
 
   PRInt32 GetInsertionIndex() { return mIndex; }
 
   void SetDefaultContent(nsIContent* aDefaultContent) { mDefaultContent = aDefaultContent; }
-  already_AddRefed<nsIContent> GetDefaultContent();
+  nsIContent* GetDefaultContent();
 
   void SetDefaultContentTemplate(nsIContent* aDefaultContent) { mDefaultContentTemplate = aDefaultContent; }
-  already_AddRefed<nsIContent> GetDefaultContentTemplate();
+  nsIContent* GetDefaultContentTemplate();
 
   void AddChild(nsIContent* aChildElement) { mElements.AppendObject(aChildElement); }
   void InsertChildAt(PRInt32 aIndex, nsIContent* aChildElement) { mElements.InsertObjectAt(aChildElement, aIndex); }
@@ -79,7 +79,7 @@ public:
   
   PRInt32 ChildCount() { return mElements.Count(); }
 
-  already_AddRefed<nsIContent> ChildAt(PRUint32 aIndex);
+  nsIContent* ChildAt(PRUint32 aIndex);
 
   PRBool Matches(nsIContent* aContent, PRUint32 aIndex);
 

dom/src/base/nsDOMClassInfo.cpp

@@ -7570,15 +7570,12 @@ nsresult
 nsArraySH::GetItemAt(nsISupports *aNative, PRUint32 aIndex,
                      nsISupports **aResult)
 {
-  nsCOMPtr<nsIDOMNodeList> list(do_QueryInterface(aNative));
+  nsCOMPtr<nsINodeList> list(do_QueryInterface(aNative));
   NS_ENSURE_TRUE(list, NS_ERROR_UNEXPECTED);
 
-  nsIDOMNode *node = nsnull; // Weak, transfer the ownership over to aResult
-  nsresult rv = list->Item(aIndex, &node);
+  NS_IF_ADDREF(*aResult = list->GetNodeAt(aIndex));
 
-  *aResult = node;
-
-  return rv;
+  return NS_OK;
 }
 
 NS_IMETHODIMP
@@ -7696,11 +7693,17 @@ nsresult
 nsHTMLCollectionSH::GetItemAt(nsISupports *aNative, PRUint32 aIndex,
                               nsISupports **aResult)
 {
+  // Common case is that we're also an nsINodeList
+  nsresult rv = nsArraySH::GetItemAt(aNative, aIndex, aResult);
+  if (NS_SUCCEEDED(rv)) {
+    return rv;
+  }
+  
   nsCOMPtr<nsIDOMHTMLCollection> collection(do_QueryInterface(aNative));
   NS_ENSURE_TRUE(collection, NS_ERROR_UNEXPECTED);
 
   nsIDOMNode *node = nsnull; // Weak, transfer the ownership over to aResult
-  nsresult rv = collection->Item(aIndex, &node);
+  rv = collection->Item(aIndex, &node);
 
   *aResult = node;