[gnome-media] Fix possible crasher with no port on a source

[Bastien Nocera <hadess src gnome org>]

commit f946961da583166e04be114a02ac456dfb5155a2
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Jul 27 16:59:59 2009 +0100

    Fix possible crasher with no port on a source

 gnome-volume-control/src/gvc-mixer-control.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gnome-volume-control/src/gvc-mixer-control.c b/gnome-volume-control/src/gvc-mixer-control.c
index 837fb05..0b5feee 100644
--- a/gnome-volume-control/src/gvc-mixer-control.c
+++ b/gnome-volume-control/src/gvc-mixer-control.c
@@ -760,7 +760,8 @@ update_source (GvcMixerControl      *control,
         gvc_mixer_stream_set_can_decibel (stream, !!(info->flags & PA_SOURCE_DECIBEL_VOLUME));
         gvc_mixer_stream_set_base_volume (stream, (guint32) info->base_volume);
 #if PA_MICRO > 15
-        gvc_mixer_stream_set_port (stream, info->active_port->name);
+        if (info->active_port != NULL)
+                gvc_mixer_stream_set_port (stream, info->active_port->name);
 #endif /* PA_MICRO > 15 */
 
         if (is_new) {