[grilo] core: set source_id if really needed

[Juan A. Suarez Romero <jasuarez src gnome org>]

commit 5ac3cfa53f1d67590c02240147ee0334316f924f
Author: Juan A. Suarez Romero <jasuarez igalia com>
Date:   Tue Nov 13 23:12:12 2012 +0000

    core: set source_id if really needed
    
    Only insert the source_id in the media if actually the source didn't insert it.

 src/grl-source.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/grl-source.c b/src/grl-source.c
index b3a8efd..3ef2c82 100644
--- a/src/grl-source.c
+++ b/src/grl-source.c
@@ -2204,7 +2204,7 @@ browse_result_relay_cb (GrlSource *source,
   }
 
   /* Set the source */
-  if (media) {
+  if (media && !grl_media_get_source (media)) {
     grl_media_set_source (media, grl_source_get_id (source));
   }