[gimp/soc-2011-seamless-clone2] app: some more precondition checks in gimpoverlaychild.c

[Clayton Walker <claytonw src gnome org>]

commit b67c9e91ed718370951340567664bc5bfa65f6cd
Author: Michael Natterer <mitch gimp org>
Date:   Sat Apr 27 00:23:04 2013 +0200

    app: some more precondition checks in gimpoverlaychild.c

 app/widgets/gimpoverlaychild.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/app/widgets/gimpoverlaychild.c b/app/widgets/gimpoverlaychild.c
index d682c5f..ebec828 100644
--- a/app/widgets/gimpoverlaychild.c
+++ b/app/widgets/gimpoverlaychild.c
@@ -140,6 +140,7 @@ gimp_overlay_child_realize (GimpOverlayBox   *box,
 
   g_return_if_fail (GIMP_IS_OVERLAY_BOX (box));
   g_return_if_fail (child != NULL);
+  g_return_if_fail (child->window == NULL);
 
   widget = GTK_WIDGET (box);
 
@@ -205,6 +206,7 @@ gimp_overlay_child_unrealize (GimpOverlayBox   *box,
 {
   g_return_if_fail (GIMP_IS_OVERLAY_BOX (box));
   g_return_if_fail (child != NULL);
+  g_return_if_fail (child->window != NULL);
 
   gdk_window_set_user_data (child->window, NULL);
   gdk_window_destroy (child->window);