[gnome-control-center] region: don't access priv pointer before checking no error

[Rui Matos <rtcm src gnome org>]

commit 8dbd9ed592770eaa498ad835d4d322b0dd38810d
Author: Cosimo Cecchi <cosimo endlessm com>
Date:   Wed Feb 10 18:17:59 2016 -0800

    region: don't access priv pointer before checking no error
    
    If the GCancellable is cancelled by the finalize() function, the
    callback will still be called potentially with an instance of the
    panel that's not valid anymore.
    To avoid crashing in that case, only access the priv pointer
    when we have no error.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=761846

 panels/region/cc-region-panel.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/panels/region/cc-region-panel.c b/panels/region/cc-region-panel.c
index f4d9241..f1b3356 100644
--- a/panels/region/cc-region-panel.c
+++ b/panels/region/cc-region-panel.c
@@ -731,19 +731,22 @@ fetch_ibus_engines_result (GObject       *object,
                            GAsyncResult  *result,
                            CcRegionPanel *self)
 {
-        CcRegionPanelPrivate *priv = self->priv;
+        CcRegionPanelPrivate *priv;
         GList *list, *l;
         GError *error;
 
         error = NULL;
-        list = ibus_bus_list_engines_async_finish (priv->ibus, result, &error);
-        g_clear_object (&priv->ibus_cancellable);
+        list = ibus_bus_list_engines_async_finish (IBUS_BUS (object), result, &error);
         if (!list && error) {
-                g_warning ("Couldn't finish IBus request: %s", error->message);
+                if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                        g_warning ("Couldn't finish IBus request: %s", error->message);
                 g_error_free (error);
                 return;
         }
 
+        priv = self->priv;
+        g_clear_object (&priv->ibus_cancellable);
+
         /* Maps engine ids to engine description objects */
         priv->ibus_engines = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_object_unref);