Set metadata to ' ' when data is mising (fixes: #122)

docs/changes.rst

@@ -20,6 +20,7 @@ v0.6.0 (in development)
 - Add Listener API, :mod:`mopidy.listeners`, to be implemented by actors
   wanting to receive events from the backend. This is a formalization of the
   ad hoc events the Last.fm scrobbler has already been using for some time.
+- Fix metadata update in Shoutcast streaming (Fixes: :issue:`122`) 
 
 
 v0.5.0 (2011-06-15)

mopidy/gstreamer.py

@@ -277,10 +277,18 @@ class GStreamer(ThreadingActor):
         taglist = gst.TagList()
         artists = [a for a in (track.artists or []) if a.name]
 
+        # Default to blank data to trick shoutcast into clearing any previous
+        # values it might have.
+        taglist[gst.TAG_ARTIST] = u' '
+        taglist[gst.TAG_TITLE] = u' '
+        taglist[gst.TAG_ALBUM] = u' '
+
         if artists:
             taglist[gst.TAG_ARTIST] = u', '.join([a.name for a in artists])
+
         if track.name:
             taglist[gst.TAG_TITLE] = track.name
+
         if track.album and track.album.name:
             taglist[gst.TAG_ALBUM] = track.album.name