don't focus the parent of the window being closed if that parent is the hidden window. this reinstates rev 1.52, bug 22658. now bug 224058. r=ere, roc

xpfe/appshell/src/nsXULWindow.cpp

@@ -466,10 +466,21 @@ NS_IMETHODIMP nsXULWindow::Destroy()
   // We need to explicitly set the focus on Windows
   nsCOMPtr<nsIBaseWindow> parent(do_QueryReferent(mParentWindow));
   if (parent) {
-    nsCOMPtr<nsIWidget> parentWidget;
-    parent->GetMainWidget(getter_AddRefs(parentWidget));
-    if (parentWidget)
-      parentWidget->PlaceBehind(eZPlacementTop, 0, PR_TRUE);
+    nsCOMPtr<nsIBaseWindow> baseHiddenWindow;
+    if (appShell) {
+      nsCOMPtr<nsIXULWindow> hiddenWindow;
+      appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
+      if (hiddenWindow)
+        baseHiddenWindow = do_GetInterface(hiddenWindow);
+    }
+    // somebody screwed up somewhere. hiddenwindow shouldn't be anybody's
+    // parent. still, when it happens, skip activating it.
+    if (baseHiddenWindow != parent) {
+      nsCOMPtr<nsIWidget> parentWidget;
+      parent->GetMainWidget(getter_AddRefs(parentWidget));
+      if (parentWidget)
+        parentWidget->PlaceBehind(eZPlacementTop, 0, PR_TRUE);
+    }
   }
 #endif