Caused by the patch from bug 295447. Steps: 0) Start TestGtkEmbed 1) type www.gnome.org in the location entry, press return 2) Wait for the page to load 3) Click in the web page area Result: (Gecko:8194): Gtk-CRITICAL **: gtk_window_present_with_time: assertion `GTK_IS_WINDOW (window)' failed Trace: (gdb) where #0 IA__g_log (log_domain=0x77df8fb7 "Gtk", log_level=2011140023, format=0x77df8fb7 "Gtk") at gmessages.c:516 #1 0x77992ffa in IA__g_return_if_fail_warning (log_domain=0x77df8fb7 "Gtk", pretty_function=0x77ea0324 "gtk_window_present_with_time", expression=0x77df8fb7 "Gtk") at gmessages.c:532 #2 0x77dee134 in IA__gtk_window_present_with_time (window=0x0, timestamp=0) at gtkwindow.c:6057 #3 0x77dee1e1 in IA__gtk_window_present (window=0x77df8fb7) at gtkwindow.c:6036 #4 0x7654de9a in nsWindow::SetFocus (this=0x83ddad0, aRaise=1) at /opt/source/mozilla/trunk/mozilla/widget/src/gtk2/nsWindow.cpp:721 #5 0x75e1d22d in nsEventStateManager::SendFocusBlur (this=0x83dd448, aPresContext=0x83dd148, aContent=0x0, aEnsureWindowHasFocus=1) at /opt/source/mozilla/trunk/mozilla/content/events/src/nsEventStateManager.cpp:4324 #6 0x75e1da62 in nsEventStateManager::SetContentState (this=0x83dd448, aContent=0x0, aState=2) at /opt/source/mozilla/trunk/mozilla/content/events/src/nsEventStateManager.cpp:3910 #7 0x75e1acaa in nsEventStateManager::PostHandleEvent (this=0x83dd448, aPresContext=0x83dd148, aEvent=0x7fbd9ab0, aTargetFrame=0x84e0244, aStatus=0x7fbd98dc, aView=0x83dda60) at /opt/source/mozilla/trunk/mozilla/content/events/src/nsEventStateManager.cpp:1976 #8 0x75b4fa22 in PresShell::HandleEventInternal (this=0x83e0c20, aEvent=0x7fbd9ab0, aView=0x83dda60, aStatus=0x7fbd98dc) at /opt/source/mozilla/trunk/mozilla/layout/base/nsPresShell.cpp:6135 #9 0x75b4fc9c in PresShell::HandlePositionedEvent (this=0x83e0c20, aView=0x83dda60, aTargetFrame=0x84e0244, aEvent=0x7fbd9ab0, aEventStatus=0x7fbd98dc) at /opt/source/mozilla/trunk/mozilla/layout/base/nsPresShell.cpp:5996 #10 0x75b50698 in PresShell::HandleEvent (this=0x83e0c20, aView=0x83dda60, aEvent=0x7fbd9ab0, aEventStatus=0x7fbd98dc) at /opt/source/mozilla/trunk/mozilla/layout/base/nsPresShell.cpp:5824 #11 0x75fb0d52 in nsViewManager::HandleEvent (this=0x83dd9e0, aView=0x83dda60, aPoint=@0x7fbd998c, aEvent=0x7fbd9ab0, aCaptured=0) at /opt/source/mozilla/trunk/mozilla/view/src/nsViewManager.cpp:1702 #12 0x75fb1c49 in nsViewManager::DispatchEvent (this=0x83dd9e0, aEvent=0x7fbd9ab0, aStatus=0x7fbd9a20) at /opt/source/mozilla/trunk/mozilla/view/src/nsViewManager.cpp:1658 #13 0x75fa439f in HandleEvent (aEvent=0x7fbd9ab0) at /opt/source/mozilla/trunk/mozilla/view/src/nsView.cpp:171 #14 0x7655a925 in nsCommonWidget::DispatchEvent (this=0x8420588, aEvent=0x7fbd9ab0, aStatus=@0x7fbd9b04) at /opt/source/mozilla/trunk/mozilla/widget/src/gtk2/nsCommonWidget.cpp:234 #15 0x76552135 in nsWindow::OnButtonPressEvent (this=0x8420588, aWidget=0x829dc20, aEvent=0x8322000) at /opt/source/mozilla/trunk/mozilla/widget/src/gtk2/nsWindow.cpp:1754 #16 0x7655223e in button_press_event_cb (widget=0x829dc20, event=0x8322000) at /opt/source/mozilla/trunk/mozilla/widget/src/gtk2/nsWindow.cpp:3994 xulrunner trunk from 2006-03-07.

I verified it with xulrunner.