[gnome-settings-daemon] power: Fix crasher when logind isn't available

[Bastien Nocera <hadess src gnome org>]

commit 92d03e224f096bd7d3b69cc8c29ac859dd46e058
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Jul 9 11:26:32 2014 +0200

    power: Fix crasher when logind isn't available
    
    We need to check for the array being non-NULL before trying to
    destroy it.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=732836

 plugins/power/gsd-power-manager.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/plugins/power/gsd-power-manager.c b/plugins/power/gsd-power-manager.c
index 7a50ef3..26ba2c1 100644
--- a/plugins/power/gsd-power-manager.c
+++ b/plugins/power/gsd-power-manager.c
@@ -2443,8 +2443,10 @@ gsd_power_manager_stop (GsdPowerManager *manager)
         g_clear_object (&manager->priv->logind_proxy);
         g_clear_object (&manager->priv->rr_screen);
 
-        g_ptr_array_unref (manager->priv->devices_array);
-        manager->priv->devices_array = NULL;
+        if (manager->priv->devices_array != NULL) {
+                g_ptr_array_unref (manager->priv->devices_array);
+                manager->priv->devices_array = NULL;
+        }
         g_clear_object (&manager->priv->device_composite);
 
         g_clear_object (&manager->priv->screensaver_proxy);