mpd: list shouldn't return blank artist names, album names, or dates

docs/changes.rst

@@ -82,6 +82,9 @@ long time been our most requested feature. Finally, it's here!
 - The MPD command ``listplaylists`` will no longer return playlists without a
   name. This could crash ncmpcpp.
 
+- The MPD command ``list`` will no longer return artist names, album names, or
+  dates that are blank.
+
 **MPRIS frontend**
 
 - The MPRIS playlists interface is now supported by our MPRIS frontend. This

mopidy/backends/dummy.py

@@ -37,9 +37,11 @@ class DummyLibraryProvider(base.BaseLibraryProvider):
     def __init__(self, *args, **kwargs):
         super(DummyLibraryProvider, self).__init__(*args, **kwargs)
         self.dummy_library = []
+        self.dummy_find_exact_result = []
+        self.dummy_search_result = []
 
     def find_exact(self, **query):
-        return []
+        return self.dummy_find_exact_result
 
     def lookup(self, uri):
         return filter(lambda t: uri == t.uri, self.dummy_library)
@@ -48,7 +50,7 @@ class DummyLibraryProvider(base.BaseLibraryProvider):
         pass
 
     def search(self, **query):
-        return []
+        return self.dummy_search_result
 
 
 class DummyPlaybackProvider(base.BasePlaybackProvider):

mopidy/frontends/mpd/protocol/music_db.py

@@ -250,7 +250,8 @@ def _list_artist(context, query):
     tracks = context.core.library.find_exact(**query).get()
     for track in tracks:
         for artist in track.artists:
-            artists.add(('Artist', artist.name))
+            if artist.name:
+                artists.add(('Artist', artist.name))
     return artists
 
 
@@ -258,7 +259,7 @@ def _list_album(context, query):
     albums = set()
     tracks = context.core.library.find_exact(**query).get()
     for track in tracks:
-        if track.album is not None:
+        if track.album and track.album.name:
             albums.add(('Album', track.album.name))
     return albums
 
@@ -267,7 +268,7 @@ def _list_date(context, query):
     dates = set()
     tracks = context.core.library.find_exact(**query).get()
     for track in tracks:
-        if track.date is not None:
+        if track.date:
             dates.add(('Date', track.date))
     return dates
 

tests/frontends/mpd/protocol/music_db_test.py

@@ -1,5 +1,7 @@
 from __future__ import unicode_literals
 
+from mopidy.models import Album, Artist, Track
+
 from tests.frontends.mpd import protocol
 
 
@@ -181,6 +183,14 @@ class MusicDatabaseListTest(protocol.BaseTestCase):
         self.sendRequest('list "artist" "artist" ""')
         self.assertInResponse('OK')
 
+    def test_list_artist_should_not_return_artists_without_names(self):
+        self.backend.library.dummy_find_exact_result = [
+            Track(artists=[Artist(name='')])]
+
+        self.sendRequest('list "artist"')
+        self.assertNotInResponse('Artist: ')
+        self.assertInResponse('OK')
+
     ### Album
 
     def test_list_album_with_quotes(self):
@@ -232,6 +242,14 @@ class MusicDatabaseListTest(protocol.BaseTestCase):
         self.sendRequest('list "album" "artist" ""')
         self.assertInResponse('OK')
 
+    def test_list_album_should_not_return_albums_without_names(self):
+        self.backend.library.dummy_find_exact_result = [
+            Track(album=Album(name=''))]
+
+        self.sendRequest('list "album"')
+        self.assertNotInResponse('Album: ')
+        self.assertInResponse('OK')
+
     ### Date
 
     def test_list_date_with_quotes(self):
@@ -279,6 +297,13 @@ class MusicDatabaseListTest(protocol.BaseTestCase):
         self.sendRequest('list "date" "artist" ""')
         self.assertInResponse('OK')
 
+    def test_list_date_should_not_return_blank_dates(self):
+        self.backend.library.dummy_find_exact_result = [Track(date='')]
+
+        self.sendRequest('list "date"')
+        self.assertNotInResponse('Date: ')
+        self.assertInResponse('OK')
+
     ### Genre
 
     def test_list_genre_with_quotes(self):