fix: an album with missing tracks is wanted back by its release group, not only when it carries a release MBID (#6167)

The release id was only ever used to find the group. 238 albums matched to a
group carried none, so their losses, five of the resolver's wrong-slot
removals among them, were never fetched again.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/db/dbq/reacquisition.sql.go

@@ -17,7 +17,7 @@ SELECT COUNT(DISTINCT albums.id)::bigint
   JOIN artists ON artists.id = albums.artist_id
   JOIN tracks  ON tracks.album_id = albums.id
  WHERE tracks.missing_since IS NOT NULL
-   AND (albums.mbid IS NULL OR artists.mbid IS NULL)
+   AND ((albums.mbid IS NULL AND albums.release_group_mbid IS NULL) OR artists.mbid IS NULL)
 `
 
 // Albums with missing files that can never be wanted automatically because
@@ -105,7 +105,7 @@ SELECT albums.id                 AS album_id,
   JOIN tracks  ON tracks.album_id = albums.id
  WHERE tracks.missing_since IS NOT NULL
    AND tracks.missing_since <= now() - make_interval(hours => $1::int)
-   AND albums.mbid IS NOT NULL
+   AND (albums.mbid IS NOT NULL OR albums.release_group_mbid IS NOT NULL)
    AND artists.mbid IS NOT NULL
  GROUP BY albums.id, albums.title, albums.mbid, albums.release_group_mbid,
           artists.name, artists.mbid
@@ -141,8 +141,11 @@ type ListAlbumsDueReacquisitionRow struct {
 //   - it still has at least one track whose file has been missing longer than
 //     the grace window. Measured on missing_since, which reconcile never
 //     re-stamps (#2523), so it is a genuine "gone since" clock;
-//   - MusicBrainz can name it: the album and its artist have MBIDs. Albums
-//     failing this are counted separately (CountAlbumsMissingWithoutMbid);
+//   - MusicBrainz can name it: the artist has an MBID, and the album a
+//     release MBID or a release group. The release MBID is only ever used to
+//     find the group, and 238 albums matched to a group carried no release
+//     id, so their losses were never wanted back (#6167). Albums failing this
+//     are counted separately (CountAlbumsMissingWithoutMbid);
 //   - it is on the wanted list (#5567): an album taken off the list, or
 //     dropped into the library by hand, is not fetched back;
 //   - no want already covers it: none open, and none held since its files

internal/db/queries/reacquisition.sql

@@ -21,8 +21,11 @@ RETURNING *;
 --   * it still has at least one track whose file has been missing longer than
 --     the grace window. Measured on missing_since, which reconcile never
 --     re-stamps (#2523), so it is a genuine "gone since" clock;
---   * MusicBrainz can name it: the album and its artist have MBIDs. Albums
---     failing this are counted separately (CountAlbumsMissingWithoutMbid);
+--   * MusicBrainz can name it: the artist has an MBID, and the album a
+--     release MBID or a release group. The release MBID is only ever used to
+--     find the group, and 238 albums matched to a group carried no release
+--     id, so their losses were never wanted back (#6167). Albums failing this
+--     are counted separately (CountAlbumsMissingWithoutMbid);
 --   * it is on the wanted list (#5567): an album taken off the list, or
 --     dropped into the library by hand, is not fetched back;
 --   * no want already covers it: none open, and none held since its files
@@ -41,7 +44,7 @@ SELECT albums.id                 AS album_id,
   JOIN tracks  ON tracks.album_id = albums.id
  WHERE tracks.missing_since IS NOT NULL
    AND tracks.missing_since <= now() - make_interval(hours => sqlc.arg(grace_hours)::int)
-   AND albums.mbid IS NOT NULL
+   AND (albums.mbid IS NOT NULL OR albums.release_group_mbid IS NOT NULL)
    AND artists.mbid IS NOT NULL
  GROUP BY albums.id, albums.title, albums.mbid, albums.release_group_mbid,
           artists.name, artists.mbid
@@ -64,7 +67,7 @@ SELECT COUNT(DISTINCT albums.id)::bigint
   JOIN artists ON artists.id = albums.artist_id
   JOIN tracks  ON tracks.album_id = albums.id
  WHERE tracks.missing_since IS NOT NULL
-   AND (albums.mbid IS NULL OR artists.mbid IS NULL);
+   AND ((albums.mbid IS NULL AND albums.release_group_mbid IS NULL) OR artists.mbid IS NULL);
 
 -- name: WantMissingAlbum :one
 -- Records an album with missing files as wanted. A held want for the same

internal/reacquisition/sweeper.go

@@ -103,7 +103,8 @@ func (s *Sweeper) SweepOnce(ctx context.Context) error {
 // want records one album as wanted under its release group.
 func (s *Sweeper) want(ctx context.Context, q *dbq.Queries, album dbq.ListAlbumsDueReacquisitionRow, res *PassResult) error {
 	// The query already filters these out; belt and braces.
-	if album.AlbumMbid == nil || album.ArtistMbid == nil {
+	hasGroup := album.AlbumReleaseGroupMbid != nil && *album.AlbumReleaseGroupMbid != ""
+	if (album.AlbumMbid == nil && !hasGroup) || album.ArtistMbid == nil {
 		return nil
 	}
 	group, err := s.albumReleaseGroup(ctx, q, album)

internal/reacquisition/sweeper_test.go

@@ -38,17 +38,21 @@ func newSweepPool(t *testing.T) *pgxpool.Pool {
 }
 
 // lostAlbum seeds an album whose only track has been missing for two days,
-// named by MusicBrainz release id and (when group is set) release group.
+// named by MusicBrainz release id (when release is set) and release group
+// (when group is set).
 func lostAlbum(t *testing.T, pool *pgxpool.Pool, title, release, group string) pgtype.UUID {
 	t.Helper()
 	ctx := context.Background()
 	q := dbq.New(pool)
-	artistMBID := "artist-" + release
+	artistMBID := "artist-" + title
 	ar, err := q.UpsertArtist(ctx, dbq.UpsertArtistParams{Name: title + " Artist", SortName: title, Mbid: &artistMBID})
 	if err != nil {
 		t.Fatal(err)
 	}
-	params := dbq.UpsertAlbumParams{Title: title, SortTitle: title, ArtistID: ar.ID, Mbid: &release}
+	params := dbq.UpsertAlbumParams{Title: title, SortTitle: title, ArtistID: ar.ID}
+	if release != "" {
+		params.Mbid = &release
+	}
 	if group != "" {
 		params.ReleaseGroupMbid = &group
 	}
@@ -58,7 +62,7 @@ func lostAlbum(t *testing.T, pool *pgxpool.Pool, title, release, group string) p
 	}
 	tr, err := q.UpsertTrack(ctx, dbq.UpsertTrackParams{
 		Title: "Lost", AlbumID: al.ID, ArtistID: ar.ID, DurationMs: 180000,
-		FilePath: "/music/" + release + "/01.flac", FileSize: 1, FileFormat: "flac",
+		FilePath: "/music/" + title + "/01.flac", FileSize: 1, FileFormat: "flac",
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -99,7 +103,11 @@ func TestSweep_WantsBackOnlyAlbumsOnTheList_Integration(t *testing.T) {
 	resolved := lostAlbum(t, pool, "Resolved", "release-resolved", "")
 	unknown := lostAlbum(t, pool, "Unknown", "release-unknown", "")
 	_ = lostAlbum(t, pool, "Off The List", "release-off", "group-off")
+	// Matched to a group with no release id: 238 such albums on the operator's
+	// library were never wanted back (#6167).
+	groupOnly := lostAlbum(t, pool, "Group Only", "", "group-only")
 	heldWant(t, pool, "group-tagged", tagged, "3 days")
+	heldWant(t, pool, "group-only", groupOnly, "3 days")
 	heldWant(t, pool, "group-resolved", resolved, "3 days")
 	heldWant(t, pool, "group-unknown", unknown, "3 days")
 
@@ -128,6 +136,7 @@ func TestSweep_WantsBackOnlyAlbumsOnTheList_Integration(t *testing.T) {
 	}
 	wantFor("group-tagged", tagged)
 	wantFor("group-resolved", resolved)
+	wantFor("group-only", groupOnly)
 	if w, _ := q.GetWantByReleaseGroup(ctx, "group-unknown"); !w.FulfilledAt.Valid {
 		t.Error("an album MusicBrainz cannot name was reopened under the wrong group")
 	}