[rygel] gstreamer: Don't crash on transcoding

[Jens Georg <jensgeorg src gnome org>]

commit 37ee7322869a5550da166f769ade8fcfda754052
Author: Jens Georg <jensg openismus com>
Date:   Sat Oct 6 17:11:31 2012 +0200

    gstreamer: Don't crash on transcoding

 .../gstreamer/rygel-gst-data-source.vala           |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/src/media-engines/gstreamer/rygel-gst-data-source.vala b/src/media-engines/gstreamer/rygel-gst-data-source.vala
index 0ee3b78..19252f4 100644
--- a/src/media-engines/gstreamer/rygel-gst-data-source.vala
+++ b/src/media-engines/gstreamer/rygel-gst-data-source.vala
@@ -43,8 +43,13 @@ internal class Rygel.GstDataSource : Rygel.DataSource, GLib.Object {
     }
 
     ~GstDataSource () {
-        this.sink.cancellable.cancel ();
-        this.pipeline.set_state (State.NULL);
+        if (this.sink != null) {
+            this.sink.cancellable.cancel ();
+        }
+
+        if (this.pipeline != null) {
+            this.pipeline.set_state (State.NULL);
+        }
     }
 
     public GstDataSource.from_element (Element element) {