[gnome-settings-daemon] power: Only emit screen brightness changed if the callout succeeded

[Richard Hughes <rhughes src gnome org>]

commit ca0d899f863659120f7b3737fc9384ec3ca4172b
Author: Richard Hughes <richard hughsie com>
Date:   Mon Sep 3 11:09:23 2012 +0100

    power: Only emit screen brightness changed if the callout succeeded
    
    Fixes one half of https://bugzilla.gnome.org/show_bug.cgi?id=674434

 plugins/power/gsd-power-manager.c |   14 ++++++++------
 1 files changed, 8 insertions(+), 6 deletions(-)
---
diff --git a/plugins/power/gsd-power-manager.c b/plugins/power/gsd-power-manager.c
index 033ab8a..6c00823 100644
--- a/plugins/power/gsd-power-manager.c
+++ b/plugins/power/gsd-power-manager.c
@@ -2671,7 +2671,7 @@ backlight_set_percentage (GsdPowerManager *manager,
                                           discrete,
                                           error);
 out:
-        if (emit_changed)
+        if (ret && emit_changed)
                 backlight_emit_changed (manager);
         return ret;
 }
@@ -2680,7 +2680,7 @@ static gint
 backlight_step_up (GsdPowerManager *manager, GError **error)
 {
         GnomeRROutput *output;
-        gboolean ret;
+        gboolean ret = FALSE;
         gint percentage_value = -1;
         gint min = 0;
         gint max;
@@ -2722,7 +2722,8 @@ backlight_step_up (GsdPowerManager *manager, GError **error)
         if (ret)
                 percentage_value = ABS_TO_PERCENTAGE (min, max, discrete);
 out:
-        backlight_emit_changed (manager);
+        if (ret)
+                backlight_emit_changed (manager);
         return percentage_value;
 }
 
@@ -2730,7 +2731,7 @@ static gint
 backlight_step_down (GsdPowerManager *manager, GError **error)
 {
         GnomeRROutput *output;
-        gboolean ret;
+        gboolean ret = FALSE;
         gint percentage_value = -1;
         gint min = 0;
         gint max;
@@ -2772,7 +2773,8 @@ backlight_step_down (GsdPowerManager *manager, GError **error)
         if (ret)
                 percentage_value = ABS_TO_PERCENTAGE (min, max, discrete);
 out:
-        backlight_emit_changed (manager);
+        if (ret)
+                backlight_emit_changed (manager);
         return percentage_value;
 }
 
@@ -2799,7 +2801,7 @@ backlight_set_abs (GsdPowerManager *manager,
                                           value,
                                           error);
 out:
-        if (emit_changed)
+        if (ret && emit_changed)
                 backlight_emit_changed (manager);
         return ret;
 }