Menus now set and unset the open attribute.

widget/src/windows/nsMenu.cpp

@@ -484,8 +484,15 @@ nsEventStatus nsMenu::MenuConstruct(
 {
    //printf("nsMenu::MenuConstruct called \n");
    // Begin menuitem inner loop
+
+  // Open the node.
+  nsCOMPtr<nsIDOMElement> domElement = do_QueryInterface(mDOMNode);
+  if (domElement)
+    domElement->SetAttribute("open", "true");
+
+  // Now get the kids
   nsCOMPtr<nsIDOMNode> menuitemNode;
-    ((nsIDOMNode*)mDOMNode)->GetFirstChild(getter_AddRefs(menuitemNode));
+  mDOMNode->GetFirstChild(getter_AddRefs(menuitemNode));
 
 	unsigned short menuIndex = 0;
 
@@ -520,6 +527,12 @@ nsEventStatus nsMenu::MenuDestruct(const nsMenuEvent & aMenuEvent)
   // We cannot call RemoveAll() yet because menu item selection may need it
   //RemoveAll();
   
+  // Close the node.
+  nsCOMPtr<nsIDOMElement> domElement = do_QueryInterface(mDOMNode);
+  if (domElement)
+    domElement->RemoveAttribute("open");
+
+  // Now remove the kids
   while (PR_TRUE) {
     PRUint32 cnt;
     nsresult rv = mItems->Count(&cnt);