[gnome-media] Avoid warning on applet startup

[Bastien Nocera <hadess src gnome org>]

commit c1807797fca7a3ef251603ed9c7af785c483f256
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Feb 2 15:07:52 2010 +0000

    Avoid warning on applet startup

 gnome-volume-control/src/gvc-mixer-control.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gnome-volume-control/src/gvc-mixer-control.c b/gnome-volume-control/src/gvc-mixer-control.c
index c1f6550..b5636d9 100644
--- a/gnome-volume-control/src/gvc-mixer-control.c
+++ b/gnome-volume-control/src/gvc-mixer-control.c
@@ -474,6 +474,10 @@ _set_default_sink (GvcMixerControl *control,
         guint new_id;
 
         if (stream == NULL) {
+                /* Don't tell front-ends about an unset default
+                 * sink if it's already unset */
+                if (control->priv->default_sink_is_set == FALSE)
+                        return;
                 control->priv->default_sink_id = 0;
                 control->priv->default_sink_is_set = FALSE;
                 g_signal_emit (control,