[rygel] media-export: Fix search

[Jens Georg <jensgeorg src gnome org>]

commit 3a50c9135e7b5df909d4236e84a11fe9bfded28f
Author: Jens Georg <jensg openismus com>
Date:   Fri Jan 18 17:41:20 2013 +0100

    media-export: Fix search

 .../rygel-media-export-media-cache.vala            |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/plugins/media-export/rygel-media-export-media-cache.vala b/src/plugins/media-export/rygel-media-export-media-cache.vala
index cf2533b..fbf2c43 100644
--- a/src/plugins/media-export/rygel-media-export-media-cache.vala
+++ b/src/plugins/media-export/rygel-media-export-media-cache.vala
@@ -356,7 +356,11 @@ public class Rygel.MediaExport.MediaCache : Object {
             unowned string parent_id = statement.column_text (DetailColumn.PARENT);
 
             if (parent == null || parent_id != parent.id) {
-                parent = new NullContainer (parent_id, null, "MediaExport");
+                if (parent_id == null) {
+                    parent = new NullContainer.root ();
+                } else {
+                    parent = new NullContainer (parent_id, null, "MediaExport");
+                }
             }
 
             if (parent != null) {