app window: test actiongroup across destroy

Make sure that we don't violate the interface contract of GActionGroup
just because gtk_widget_destroy() was called.

https://bugzilla.gnome.org/show_bug.cgi?id=710351

testsuite/gtk/Makefile.am

@@ -39,6 +39,7 @@ TEST_PROGS += 			\
 	floating		\
 	grid			\
 	gtkmenu			\
+	gtkapplicationwindow	\
 	keyhash			\
 	listbox			\
 	no-gtk-init		\

testsuite/gtk/gtkapplicationwindow.c

@@ -0,0 +1,81 @@
+#include <gtk/gtk.h>
+
+static void
+removed (GActionGroup *group,
+         const gchar  *name,
+         gpointer      user_data)
+{
+  gboolean *was_removed = user_data;
+
+  *was_removed = TRUE;
+}
+
+static void
+test_as_actiongroup (void)
+{
+  GSimpleAction *action;
+  gboolean was_removed;
+  gpointer window;
+  gchar **list;
+
+  /* do a dummy round... */
+  window = g_object_ref_sink (g_object_new (GTK_TYPE_APPLICATION_WINDOW, NULL));
+  gtk_widget_destroy (window);
+  g_object_unref (window);
+
+  /* create a window, add an action */
+  window = g_object_ref_sink (g_object_new (GTK_TYPE_APPLICATION_WINDOW, NULL));
+  action = g_simple_action_new ("foo", NULL);
+  g_action_map_add_action (window, G_ACTION (action));
+  g_object_unref (action);
+
+  /* check which actions we have in the group */
+  list = g_action_group_list_actions (window);
+  g_assert_cmpstr (list[0], ==, "foo");
+  g_assert_cmpstr (list[1], ==, NULL);
+  g_strfreev (list);
+
+  /* make sure that destroying the window keeps our view of the actions
+   * consistent.
+   */
+  g_signal_connect (window, "action-removed", G_CALLBACK (removed), &was_removed);
+  gtk_widget_destroy (window);
+
+  /* One of two things will have happened, depending on the
+   * implementation.  Both are valid:
+   *
+   *  - we received a signal that the action was removed when we
+   *    destroyed the window; or
+   *
+   *  - the action is still available.
+   *
+   * Make sure we're in one of those states.
+   *
+   * This additionally ensures that calling into methods on the window
+   * will continue to work after it has been destroy (and not segfault).
+   */
+  list = g_action_group_list_actions (window);
+
+  if (was_removed == FALSE)
+    {
+      /* should still be here */
+      g_assert_cmpstr (list[0], ==, "foo");
+      g_assert_cmpstr (list[1], ==, NULL);
+    }
+  else
+    /* should be gone */
+    g_assert_cmpstr (list[0], ==, NULL);
+
+  g_object_unref (window);
+  g_strfreev (list);
+}
+
+int
+main (int argc, char **argv)
+{
+  gtk_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/gtkapplicationwindow/as-actiongroup", test_as_actiongroup);
+
+  return g_test_run ();
+}