diff --git a/mozilla/content/html/document/src/nsHTMLDocument.cpp b/mozilla/content/html/document/src/nsHTMLDocument.cpp
index 17e072e93de..353318b1cf7 100644
--- a/mozilla/content/html/document/src/nsHTMLDocument.cpp
+++ b/mozilla/content/html/document/src/nsHTMLDocument.cpp
@@ -242,6 +242,14 @@ public:
     if (mNameContentList && mNameContentList != NAME_NOT_VALID) {
       NS_RELEASE(mNameContentList);
     }
+
+    if (mIdContentList.Count() != 1 ||
+        mIdContentList[0] != ID_NOT_IN_DOCUMENT) {
+      for (PRInt32 i = 0; i < mIdContentList.Count(); ++i) {
+        nsIContent* content = static_cast<nsIContent*>(mIdContentList[i]);
+        NS_RELEASE(content);
+      }
+    }
   }
 
   nsIContent* GetIdContent() {
@@ -253,8 +261,11 @@ public:
   PRBool RemoveIdContent(nsIContent* aContent) {
     // XXXbz should this ever Compact() I guess when all the content is gone
     // we'll just get cleaned up in the natural order of things...
-    return mIdContentList.RemoveElement(aContent) &&
-      mIdContentList.Count() == 0;
+    if (!mIdContentList.RemoveElement(aContent)) {
+      return PR_FALSE;
+    }
+    NS_RELEASE(aContent);
+    return mIdContentList.Count() == 0;
   }
 
   void FlagIDNotInDocument() {
@@ -264,10 +275,13 @@ public:
     mIdContentList.AppendElement(ID_NOT_IN_DOCUMENT);
   }
 
+  void Traverse(nsCycleCollectionTraversalCallback* cb);
+
   nsCOMPtr<nsIAtom> mKey;
   nsBaseContentList *mNameContentList;
   nsRefPtr<nsContentList> mDocAllList;
 private:
+  // The content nodes are stored addrefed.
   nsSmallVoidArray mIdContentList;
 };
 
@@ -282,12 +296,20 @@ IdAndNameMapEntry::AddIdContent(nsIContent* aContent)
 
   if (GetIdContent() == ID_NOT_IN_DOCUMENT) {
     NS_ASSERTION(mIdContentList.Count() == 1, "Bogus count");
-    return mIdContentList.ReplaceElementAt(aContent, 0);
+    if (!mIdContentList.ReplaceElementAt(aContent, 0)) {
+      return PR_FALSE;
+    }
+    NS_ADDREF(aContent);
+    return PR_TRUE;
   }
 
   // Common case
   if (mIdContentList.Count() == 0) {
-    return mIdContentList.AppendElement(aContent);
+    if (!mIdContentList.AppendElement(aContent)) {
+      return PR_FALSE;
+    }
+    NS_ADDREF(aContent);
+    return PR_TRUE;
   }
 
   // We seem to have multiple content nodes for the same id, or we're doing our
@@ -314,7 +336,11 @@ IdAndNameMapEntry::AddIdContent(nsIContent* aContent)
     }
   } while (start != end);
   
-  return mIdContentList.InsertElementAt(aContent, start);
+  if (!mIdContentList.InsertElementAt(aContent, start)) {
+    return PR_FALSE;
+  }
+  NS_ADDREF(aContent);
+  return PR_TRUE;
 }
 
 
@@ -388,15 +414,26 @@ IdAndNameMapEntryTraverse(PLDHashTable *table, PLDHashEntryHdr *hdr,
   nsCycleCollectionTraversalCallback *cb =
     static_cast<nsCycleCollectionTraversalCallback*>(arg);
   IdAndNameMapEntry *entry = static_cast<IdAndNameMapEntry*>(hdr);
-
-  if (entry->mNameContentList != NAME_NOT_VALID)
-    cb->NoteXPCOMChild(entry->mNameContentList);
-
-  cb->NoteXPCOMChild(static_cast<nsIDOMNodeList*>(entry->mDocAllList));
+  entry->Traverse(cb);
 
   return PL_DHASH_NEXT;
 }
 
+void
+IdAndNameMapEntry::Traverse(nsCycleCollectionTraversalCallback* cb)
+{
+  if (mNameContentList != NAME_NOT_VALID)
+    cb->NoteXPCOMChild(mNameContentList);
+
+  cb->NoteXPCOMChild(static_cast<nsIDOMNodeList*>(mDocAllList));
+
+  if (mIdContentList.Count() != 1 || mIdContentList[0] != ID_NOT_IN_DOCUMENT) {
+    for (PRInt32 i = 0; i < mIdContentList.Count(); ++i) {
+      cb->NoteXPCOMChild(static_cast<nsIContent*>(mIdContentList[i]));
+    }
+  }
+}
+
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHTMLDocument, nsDocument)
   if (tmp->mIdAndNameHashTable.ops) {
     PL_DHashTableEnumerate(&tmp->mIdAndNameHashTable,
@@ -4805,3 +4842,13 @@ nsHTMLDocument::CreateElem(nsIAtom *aName, nsIAtom *aPrefix,
                                 aDocumentDefaultType, aResult);
 }
 #endif
+
+void
+nsHTMLDocument::Destroy()
+{
+  nsDocument::Destroy();
+
+  // Try really really hard to make sure we don't leak things through
+  // mIdAndNameHashTable
+  InvalidateHashTables();
+}
diff --git a/mozilla/content/html/document/src/nsHTMLDocument.h b/mozilla/content/html/document/src/nsHTMLDocument.h
index 723d2996860..fe342295028 100644
--- a/mozilla/content/html/document/src/nsHTMLDocument.h
+++ b/mozilla/content/html/document/src/nsHTMLDocument.h
@@ -201,6 +201,8 @@ public:
                               nsIContent** aResult);
 #endif
 
+  virtual NS_HIDDEN_(void) Destroy();
+
   nsresult ChangeContentEditableCount(nsIContent *aElement, PRInt32 aChange);
 
   virtual EditingState GetEditingState()