Bug 329675 gtk assertion `GTK_IS_WINDOW (window)' failure

r+sr=roc

widget/src/gtk2/nsWindow.cpp

@@ -704,7 +704,7 @@ nsWindow::SetFocus(PRBool aRaise)
         // Set focus to the window
         if (gRaiseWindows && aRaise && toplevelWidget &&
             !GTK_WIDGET_HAS_FOCUS(toplevelWidget) &&
-            !mNeedsResize)
+            !mNeedsResize && GTK_IS_WINDOW(owningWindow->mShell))
           gtk_window_present(GTK_WINDOW(owningWindow->mShell));
         
         gtk_widget_grab_focus(owningWidget);