[gnome-control-center] [background] Don't use iter if you didn't get one

[William Jon McCann <mccann src gnome org>]

commit 7ecc6029ccfa40a5f9665048d2e9748298deca01
Author: William Jon McCann <jmccann redhat com>
Date:   Mon Nov 1 19:07:03 2010 -0400

    [background] Don't use iter if you didn't get one

 panels/background/cc-background-panel.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/panels/background/cc-background-panel.c b/panels/background/cc-background-panel.c
index e8e6311..0fdb901 100644
--- a/panels/background/cc-background-panel.c
+++ b/panels/background/cc-background-panel.c
@@ -546,7 +546,10 @@ style_changed_cb (GtkComboBox       *box,
   GtkTreeIter iter;
   gint value;
 
-  gtk_combo_box_get_active_iter (box, &iter);
+  if (!gtk_combo_box_get_active_iter (box, &iter))
+    {
+      return;
+    }
 
   model = gtk_combo_box_get_model (box);