[rygel] media-export: Make DVDTrack an UpdatableObject

[Jens Georg <jensgeorg src gnome org>]

commit f8aa4f8915db8f0c20691a74144a1aca8027a115
Author: Jens Georg <mail jensge org>
Date:   Sat Feb 13 21:42:36 2016 +0100

    media-export: Make DVDTrack an UpdatableObject
    
    Signed-off-by: Jens Georg <mail jensge org>

 .../media-export/rygel-media-export-dvd-track.vala |    9 ++++++++-
 .../rygel-media-export-video-item.vala             |    2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/media-export/rygel-media-export-dvd-track.vala 
b/src/plugins/media-export/rygel-media-export-dvd-track.vala
index b4e75b2..04e843e 100644
--- a/src/plugins/media-export/rygel-media-export-dvd-track.vala
+++ b/src/plugins/media-export/rygel-media-export-dvd-track.vala
@@ -22,7 +22,7 @@
 
 using GUPnP;
 
-internal class Rygel.MediaExport.DVDTrack : Rygel.VideoItem {
+internal class Rygel.MediaExport.DVDTrack : VideoItem {
     public Xml.Node* node { private get; construct set; }
     public int track { private get; construct set; }
 
@@ -88,4 +88,11 @@ internal class Rygel.MediaExport.DVDTrack : Rygel.VideoItem {
 
         return res;
     }
+
+    public override async void commit_custom (bool override_guarded)
+                                              throws Error {
+        if (this.node == null) {
+            yield base.commit_custom (override_guarded);
+        }
+    }
 }
diff --git a/src/plugins/media-export/rygel-media-export-video-item.vala 
b/src/plugins/media-export/rygel-media-export-video-item.vala
index a08e369..0ee672c 100644
--- a/src/plugins/media-export/rygel-media-export-video-item.vala
+++ b/src/plugins/media-export/rygel-media-export-video-item.vala
@@ -35,7 +35,7 @@ internal class Rygel.MediaExport.VideoItem : Rygel.VideoItem,
         yield this.commit_custom (true);
     }
 
-    public async void commit_custom (bool override_guarded) throws Error {
+    public virtual async void commit_custom (bool override_guarded) throws Error {
         this.changed ();
         var cache = MediaCache.get_default ();
         cache.save_item (this, override_guarded);