fix searching when to tags are present

beets/autotag/hooks.py

@@ -117,7 +117,8 @@ def _item_candidates(item, artist, title):
     out = []
 
     # MusicBrainz candidates.
-    out.extend(mb.match_track(artist, title))
+    if artist and title:
+        out.extend(mb.match_track(artist, title))
 
     # Plugin candidates.
     out.extend(plugins.item_candidates(item))

beets/autotag/match.py

@@ -17,7 +17,6 @@ releases and tracks.
 """
 import logging
 import re
-import copy
 from munkres import Munkres
 from unidecode import unidecode
 

beets/autotag/mb.py

@@ -157,6 +157,10 @@ def match_album(artist, album, tracks=None, limit=SEARCH_LIMIT):
     if tracks is not None:
         criteria['tracks'] = str(tracks)
 
+    # Abort if we have no search terms.
+    if not any(criteria.itervalues()):
+        return
+
     _adapt_criteria(criteria)
     res = musicbrainz3.release_search(limit=limit, **criteria)
     for release in res['release-list']:
@@ -173,6 +177,9 @@ def match_track(artist, title, limit=SEARCH_LIMIT):
         'recording': title,
     }
 
+    if not any(criteria.itervalues()):
+        return
+
     _adapt_criteria(criteria)
     res = musicbrainz3.recording_search(limit=limit, **criteria)
     for recording in res['recording-list']: