[gtk+] Do not access an invalid ActionGroup. Closes #624362.

[Jonh Wendell <jwendell src gnome org>]

commit 5c2966dda3fbe020e9d14fb1cb082446b6820ad6
Author: Jonh Wendell <jwendell gnome org>
Date:   Wed Jul 14 14:45:42 2010 -0300

    Do not access an invalid ActionGroup. Closes #624362.

 gtk/gtkapplication.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkapplication.c b/gtk/gtkapplication.c
index a0864bd..a59e236 100644
--- a/gtk/gtkapplication.c
+++ b/gtk/gtkapplication.c
@@ -165,6 +165,9 @@ gtk_application_default_action (GtkApplication *application,
   GtkApplicationPrivate *priv = application->priv;
   GtkAction *action;
 
+  if (!priv->main_actions)
+    return;
+
   action = gtk_action_group_get_action (priv->main_actions, action_name);
   if (action)
     gtk_action_activate (action);