[mutter/gnome-3-24] monitor-manager: Fix crash when UPower is not available

[Bastien Nocera <hadess src gnome org>]

commit 2ec91abf38b3b055a735318c45f7e38d9408c1be
Author: Bastien Nocera <hadess hadess net>
Date:   Wed May 31 15:17:01 2017 +0200

    monitor-manager: Fix crash when UPower is not available
    
    Don't access the upower client if it doesn't exist
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780407

 src/backends/meta-monitor-manager.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index 0d1bb05..eecef77 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -260,6 +260,9 @@ lid_is_closed_changed (UpClient   *client,
 static gboolean
 meta_monitor_manager_real_is_lid_closed (MetaMonitorManager *manager)
 {
+  if (!manager->up_client)
+    return FALSE;
+
   return up_client_get_lid_is_closed (manager->up_client);
 }