[gtk+] gdkwindow: Don't add the same window to "update_windows" twice

[Marek Kašík <mkasik src gnome org>]

commit ccd6e1ba470919a886e7faa15f9e5ea3d8c23f29
Author: Marek Kasik <mkasik redhat com>
Date:   Wed Dec 18 12:23:28 2013 +0100

    gdkwindow: Don't add the same window to "update_windows" twice
    
    This prevents passing of such window to another GMainLoop.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=711552

 gdk/gdkwindow.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 424b824..d1216b3 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -3227,6 +3227,15 @@ gdk_window_add_update_window (GdkWindow *window)
   GSList *prev = NULL;
   gboolean has_ancestor_in_list = FALSE;
 
+  /*  Check whether "window" is already in "update_windows" list.
+   *  It could be added during execution of gtk_widget_destroy() when
+   *  setting focus widget to NULL and redrawing old focus widget.
+   *  See bug 711552.
+   */
+  tmp = g_slist_find (update_windows, window);
+  if (tmp != NULL)
+    return;
+
   for (tmp = update_windows; tmp; tmp = tmp->next)
     {
       GdkWindow *parent = window->parent;