x11: Fix wrong condition when unsetting transient-for

Setting a new transient-for parent is only possible if the given parent
window is valid, not when it is NULL or valid.

diff --git a/gdk/x11/gdkwindow-x11.c b/gdk/x11/gdkwindow-x11.c
index c6d6e30f7bcdc446679cba98476194640f173017..9300fed6d0ec7434f86eefa5481365e5417b3648 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 (!parent || !GDK_WINDOW_DESTROYED (parent))
+  if (parent && !GDK_WINDOW_DESTROYED (parent))
     XSetTransientForHint (GDK_WINDOW_XDISPLAY (window), 
                          GDK_WINDOW_XID (window),
                          GDK_WINDOW_XID (parent));