[gtk+] container: don't leak the focus_child ref count

[Stefan Kost <stefkost src gnome org>]

commit b00b1c33a307f242f051de2e6117a533d141d37f
Author: Stefan Kost <ensonic users sf net>
Date:   Fri Aug 20 13:48:17 2010 +0300

    container: don't leak the focus_child ref count
    
    gtk_conatiner_set_focus_child() takes a ref. Release the ref in _destroy().
    Fixes #414712.

 gtk/gtkcontainer.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkcontainer.c b/gtk/gtkcontainer.c
index a2346ff..0a1f705 100644
--- a/gtk/gtkcontainer.c
+++ b/gtk/gtkcontainer.c
@@ -1078,6 +1078,12 @@ gtk_container_destroy (GtkObject *object)
   if (GTK_CONTAINER_RESIZE_PENDING (container))
     _gtk_container_dequeue_resize_handler (container);
 
+  if (container->focus_child)
+    {
+      g_object_unref (container->focus_child);
+      container->focus_child = NULL;
+    }
+
   /* do this before walking child widgets, to avoid
    * removing children from focus chain one by one.
    */