[gdm] manager: make sure to explicitly close user sessions in dispose

[Ray Strode <halfline src gnome org>]

commit f9c438cc5232ad7babff031d3fae6ca405239608
Author: Ray Strode <rstrode redhat com>
Date:   Wed Mar 4 11:17:05 2015 -0500

    manager: make sure to explicitly close user sessions in dispose
    
    We don't want ref count leaks to lead to unkilled sessions.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=745975

 daemon/gdm-manager.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c
index ae42619..3a1bd86 100644
--- a/daemon/gdm-manager.c
+++ b/daemon/gdm-manager.c
@@ -2701,6 +2701,10 @@ gdm_manager_dispose (GObject *object)
         g_clear_object (&manager->priv->local_factory);
         g_hash_table_unref (manager->priv->open_reauthentication_requests);
         g_hash_table_unref (manager->priv->transient_sessions);
+
+        g_list_foreach (manager->priv->user_sessions,
+                        (GFunc) gdm_session_close,
+                        NULL);
         g_list_free_full (manager->priv->user_sessions, (GDestroyNotify) g_object_unref);
         manager->priv->user_sessions = NULL;