Explicitly check for None (core playlists API future proofing).

docs/changelog.rst

@@ -39,6 +39,9 @@ Feature release.
 - MPD: Added Unix domain sockets for binding MPD to.
   (Fixes: :issue:`1531`, PR: :issue:`1629`)
 
+- MPD: Lookup track metadata for MPD ``load`` and ``listplaylistinfo``.
+  (PR:1621 :issue:`1511`)
+
 - Ensure that decoding of OS errors with unknown encoding never crashes, but
   instead replaces unknown bytes with a replacement marker. (Fixes:
   :issue:`1599`)

mopidy/mpd/protocol/stored_playlists.py

@@ -20,7 +20,7 @@ def _get_playlist(context, name, must_exist=True):
     uri = context.lookup_playlist_uri_from_name(name)
     if uri:
         playlist = context.core.playlists.lookup(uri).get()
-    if must_exist and not playlist:
+    if must_exist and playlist is None:
         raise exceptions.MpdNoExistError('No such playlist')
     return playlist
 

tests/mpd/protocol/test_stored_playlists.py

@@ -263,10 +263,10 @@ class PlaylistsHandlerTest(protocol.BaseTestCase):
         self.send_request('load "A-list"')
 
         tracks = self.core.tracklist.tracks.get()
-        self.assertEqual(1, len(tracks))
-        self.assertEqual('dummy:a', tracks[0].uri)
-        self.assertEqual('Track A', tracks[0].name)
-        self.assertEqual(5000, tracks[0].length)
+        self.assertEqual(len(tracks), 1)
+        self.assertEqual(tracks[0].uri, 'dummy:a')
+        self.assertEqual(tracks[0].name, 'Track A')
+        self.assertEqual(tracks[0].length, 5000)
 
         self.assertInResponse('OK')
 
@@ -397,7 +397,7 @@ class PlaylistsHandlerTest(protocol.BaseTestCase):
             "dummy:c",
             self.backend.playlists.get_items('dummy:a1').get()[0].uri)
 
-    def test_playlistmove_save_falis(self):
+    def test_playlistmove_save_fails(self):
         tracks = [
             Track(uri='dummy:a'),
             Track(uri='dummy:b'),