[gnome-settings-daemon] power: Avoid warnings without backlights

[Bastien Nocera <hadess src gnome org>]

commit 06fc5dd9ed21c307ebb151d14097a533a5bcb4e5
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Sep 8 10:43:51 2011 +0100

    power: Avoid warnings without backlights
    
    We really want to set an error here, so that it can
    be propagated to the screen panel in the gnome-control-center
    properly.

 plugins/power/gsd-power-manager.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/plugins/power/gsd-power-manager.c b/plugins/power/gsd-power-manager.c
index 80afa87..72eae6b 100644
--- a/plugins/power/gsd-power-manager.c
+++ b/plugins/power/gsd-power-manager.c
@@ -2256,8 +2256,17 @@ backlight_helper_get_value (const gchar *argument, GError **error)
                                          error);
         g_debug ("executed %s retval: %i", command, exit_status);
 
-        if (!ret || WEXITSTATUS (exit_status) != 0)
+        if (!ret)
+                goto out;
+
+        if (WEXITSTATUS (exit_status) != 0) {
+                 g_set_error (error,
+                             GSD_POWER_MANAGER_ERROR,
+                             GSD_POWER_MANAGER_ERROR_FAILED,
+                             "gsd-backlight-helper failed: %s",
+                             stdout_data);
                 goto out;
+        }
 
         /* parse */
         value = g_ascii_strtoll (stdout_data, &endptr, 10);