x11: Guard against NULL window

Otherwise, the NULL parent window causes a crash in the
GDK_WINDOW_IS_DESTROYED call.

diff --git a/gdk/x11/gdkwindow-x11.c b/gdk/x11/gdkwindow-x11.c
index f2e23df5fe6ff2ecb479dc40ec066e18ca1b7f27..c6d6e30f7bcdc446679cba98476194640f173017 100644 (file)
--- a/gdk/x11/gdkwindow-x11.c
+++ b/gdk/x11/gdkwindow-x11.c
@@ -2453,7 +2453,7 @@ gdk_x11_window_set_transient_for (GdkWindow *window,
     return;
 
   /* XSetTransientForHint() doesn't allow unsetting, so do it manually */
-  if (!GDK_WINDOW_DESTROYED (parent))
+  if (!parent || !GDK_WINDOW_DESTROYED (parent))
     XSetTransientForHint (GDK_WINDOW_XDISPLAY (window), 
                          GDK_WINDOW_XID (window),
                          GDK_WINDOW_XID (parent));