[gnome-settings-daemon] sharing: Fix warning on session exit

[Bastien Nocera <hadess src gnome org>]

commit 46efb26c1d0c59e1663c49f8fd61e2ab5d0aa7de
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Oct 13 12:09:41 2016 +0200

    sharing: Fix warning on session exit
    
    When exiting, the skeleton will call to stop the manager. After the
    daemon is stopped, finalize() will call _stop() again, which will fail
    because we've already closed the D-Bus connection.
    
    gsd-sharing[1865]: About to stop gnome-user-share-webdav
    gsd-sharing[1865]: g_dbus_connection_call_internal: assertion 'G_IS_DBUS_CONNECTION (connection)' failed
    gsd-sharing[1865]: About to stop rygel
    gsd-sharing[1865]: g_dbus_connection_call_internal: assertion 'G_IS_DBUS_CONNECTION (connection)' failed
    gsd-sharing[1865]: About to stop vino-server
    gsd-sharing[1865]: g_dbus_connection_call_internal: assertion 'G_IS_DBUS_CONNECTION (connection)' failed

 plugins/sharing/gsd-sharing-manager.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/plugins/sharing/gsd-sharing-manager.c b/plugins/sharing/gsd-sharing-manager.c
index b2b6086..a9ce7d7 100644
--- a/plugins/sharing/gsd-sharing-manager.c
+++ b/plugins/sharing/gsd-sharing-manager.c
@@ -720,8 +720,11 @@ gsd_sharing_manager_stop (GsdSharingManager *manager)
 {
         g_debug ("Stopping sharing manager");
 
-        manager->priv->sharing_status = GSD_SHARING_STATUS_OFFLINE;
-        gsd_sharing_manager_sync_services (manager);
+        if (manager->priv->sharing_status == GSD_SHARING_STATUS_AVAILABLE &&
+            manager->priv->connection != NULL) {
+                manager->priv->sharing_status = GSD_SHARING_STATUS_OFFLINE;
+                gsd_sharing_manager_sync_services (manager);
+        }
 
         if (manager->priv->cancellable) {
                 g_cancellable_cancel (manager->priv->cancellable);