tagging: fix list albumartists field

Author: snejus

beets/autotag/__init__.py

@@ -313,21 +313,20 @@ def apply_metadata(
 
         # MusicBrainz IDs.
         item.mb_trackid = track_info.track_id
-        item.mb_releasetrackid = track_info.release_track_id
-        item.mb_albumid = album_info.album_id
-        if track_info.artist_id:
-            item.mb_artistid = track_info.artist_id
-        else:
-            item.mb_artistid = album_info.artist_id
+        item.mb_releasetrackid = track_info.release_track_id or item.mb_trackid
 
-        if track_info.artists_ids:
-            item.mb_artistids = track_info.artists_ids
-        else:
-            item.mb_artistids = album_info.artists_ids
+        item.mb_albumid = album_info.album_id
+        item.mb_releasegroupid = album_info.releasegroup_id
 
         item.mb_albumartistid = album_info.artist_id
-        item.mb_albumartistids = album_info.artists_ids
-        item.mb_releasegroupid = album_info.releasegroup_id
+        item.mb_albumartistids = album_info.artists_ids or (
+            [ai] if (ai := item.mb_albumartistid) else []
+        )
+
+        item.mb_artistid = track_info.artist_id or item.mb_albumartistid
+        item.mb_artistids = track_info.artists_ids or (
+            [iai] if (iai := item.mb_artistid) else []
+        )
 
         # Compilation flag.
         item.comp = album_info.va

beets/importer/tasks.py

@@ -428,14 +428,17 @@ def align_album_level_fields(self):
         elif self.choice_flag in (Action.APPLY, Action.RETAG):
             # Applying autotagged metadata. Just get AA from the first
             # item.
-            if not self.items[0].albumartist:
-                changes["albumartist"] = self.items[0].artist
-            if not self.items[0].albumartists:
-                changes["albumartists"] = self.items[0].artists
-            if not self.items[0].mb_albumartistid:
-                changes["mb_albumartistid"] = self.items[0].mb_artistid
-            if not self.items[0].mb_albumartistids:
-                changes["mb_albumartistids"] = self.items[0].mb_artistids
+            first = self.items[0]
+            if not first.albumartist:
+                changes["albumartist"] = first.artist
+            if not first.albumartists:
+                changes["albumartists"] = first.artists or [first.artist]
+            if not first.mb_albumartistid:
+                changes["mb_albumartistid"] = first.mb_artistid
+            if not first.mb_albumartistids:
+                changes["mb_albumartistids"] = first.mb_artistids or [
+                    first.mb_artistid
+                ]
 
         # Apply new metadata.
         for item in self.items:

test/plugins/test_edit.py

@@ -319,13 +319,8 @@ def test_edit_apply_asis(self):
         self.assertItemFieldsModified(
             self.lib.items(),
             self.items_orig,
-            ["title"],
-            self.IGNORED
-            + [
-                "albumartist",
-                "mb_albumartistid",
-                "mb_albumartistids",
-            ],
+            ["title", "albumartist", "albumartists"],
+            self.IGNORED + ["mb_albumartistid", "mb_albumartistids"],
         )
         assert all("Edited Track" in i.title for i in self.lib.items())