fix: same-titled albums of two release groups are two albums, and a missing track with no disc is on disc 1

The scanner found an album by artist and title alone, so Weezer's six
self-titled albums (1994–2026) were one 118-track row and their merges,
wants and upgrades counted them as one. A same-named row whose release group
is known and differs from the file's is now another album; tagReadVersion 7
re-reads the library so existing tracks move to their own rows.

WantHoldings compared discs with IS NOT DISTINCT FROM, so a missing track 6
with no disc was never covered by a present disc 1 track 6. Air's Love 2
stayed wanted and was downloaded again for nothing.

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

internal/db/dbq/albums.sql.go

@@ -72,17 +72,27 @@ func (q *Queries) DeleteAlbumIfEmpty(ctx context.Context, id pgtype.UUID) (Delet
 }
 
 const getAlbumByArtistAndTitle = `-- name: GetAlbumByArtistAndTitle :one
-SELECT id, title, sort_title, artist_id, release_date, mbid, cover_art_path, created_at, updated_at, cover_art_source, cover_art_sources_version, release_group_mbid FROM albums WHERE artist_id = $1 AND title = $2 LIMIT 1
+SELECT id, title, sort_title, artist_id, release_date, mbid, cover_art_path, created_at, updated_at, cover_art_source, cover_art_sources_version, release_group_mbid FROM albums
+ WHERE artist_id = $1 AND title = $2
+   AND ($3::text IS NULL OR release_group_mbid IS NULL
+        OR release_group_mbid = $3)
+ ORDER BY (release_group_mbid IS NOT DISTINCT FROM $3) DESC, id
+ LIMIT 1
 `
 
 type GetAlbumByArtistAndTitleParams struct {
-	ArtistID pgtype.UUID
-	Title    string
+	ArtistID         pgtype.UUID
+	Title            string
+	ReleaseGroupMbid *string
 }
 
-// Scanner uses this for the no-mbid dedupe path: resolve-or-create.
+// Scanner uses this for the no-mbid dedupe path: resolve-or-create. An album
+// of the same name in another release group is a different album (Weezer's
+// six self-titled albums shared one row until 2026-10-20), so a row whose
+// group is known and differs is not returned. A row of the file's own group
+// comes first, then one with no group yet.
 func (q *Queries) GetAlbumByArtistAndTitle(ctx context.Context, arg GetAlbumByArtistAndTitleParams) (Album, error) {
-	row := q.db.QueryRow(ctx, getAlbumByArtistAndTitle, arg.ArtistID, arg.Title)
+	row := q.db.QueryRow(ctx, getAlbumByArtistAndTitle, arg.ArtistID, arg.Title, arg.ReleaseGroupMbid)
 	var i Album
 	err := row.Scan(
 		&i.ID,

internal/db/dbq/wanted.sql.go

@@ -1572,11 +1572,13 @@ SELECT a.id AS album_id,
        COALESCE(bool_or(t.missing_since IS NOT NULL AND t.missing_since < $1::timestamptz), false)::bool AS missing_before,
        -- Missing tracks no track on disk stands in for, by position or
        -- title. A missing row whose song is back at a new path (#5245) is
-       -- covered; a lost bonus track is not.
+       -- covered; a lost bonus track is not. A track with no disc number is
+       -- on disc 1: Air's Love 2 stayed wanted, and was downloaded again for
+       -- nothing, over a missing track 6 with no disc beside a present 1/6.
        COUNT(*) FILTER (WHERE t.missing_since IS NOT NULL AND NOT EXISTS (
            SELECT 1 FROM tracks p
             WHERE p.album_id = a.id AND p.missing_since IS NULL
-              AND ((p.track_number = t.track_number AND p.disc_number IS NOT DISTINCT FROM t.disc_number)
+              AND ((p.track_number = t.track_number AND COALESCE(p.disc_number, 1) = COALESCE(t.disc_number, 1))
                    OR lower(p.title) = lower(t.title))))::int AS uncovered_missing
   FROM albums a
   JOIN tracks t ON t.album_id = a.id

internal/db/queries/albums.sql

@@ -36,8 +36,17 @@ WHERE albums.artist_id = $1
 ORDER BY release_date NULLS LAST, sort_title;
 
 -- name: GetAlbumByArtistAndTitle :one
--- Scanner uses this for the no-mbid dedupe path: resolve-or-create.
-SELECT * FROM albums WHERE artist_id = $1 AND title = $2 LIMIT 1;
+-- Scanner uses this for the no-mbid dedupe path: resolve-or-create. An album
+-- of the same name in another release group is a different album (Weezer's
+-- six self-titled albums shared one row until 2026-10-20), so a row whose
+-- group is known and differs is not returned. A row of the file's own group
+-- comes first, then one with no group yet.
+SELECT * FROM albums
+ WHERE artist_id = sqlc.arg(artist_id) AND title = sqlc.arg(title)
+   AND (sqlc.narg(release_group_mbid)::text IS NULL OR release_group_mbid IS NULL
+        OR release_group_mbid = sqlc.narg(release_group_mbid))
+ ORDER BY (release_group_mbid IS NOT DISTINCT FROM sqlc.narg(release_group_mbid)) DESC, id
+ LIMIT 1;
 
 -- name: ListAlbumsByArtist :many
 SELECT * FROM albums WHERE artist_id = $1 ORDER BY release_date NULLS LAST, sort_title;

internal/db/queries/wanted.sql

@@ -146,11 +146,13 @@ SELECT a.id AS album_id,
        COALESCE(bool_or(t.missing_since IS NOT NULL AND t.missing_since < sqlc.arg(since)::timestamptz), false)::bool AS missing_before,
        -- Missing tracks no track on disk stands in for, by position or
        -- title. A missing row whose song is back at a new path (#5245) is
-       -- covered; a lost bonus track is not.
+       -- covered; a lost bonus track is not. A track with no disc number is
+       -- on disc 1: Air's Love 2 stayed wanted, and was downloaded again for
+       -- nothing, over a missing track 6 with no disc beside a present 1/6.
        COUNT(*) FILTER (WHERE t.missing_since IS NOT NULL AND NOT EXISTS (
            SELECT 1 FROM tracks p
             WHERE p.album_id = a.id AND p.missing_since IS NULL
-              AND ((p.track_number = t.track_number AND p.disc_number IS NOT DISTINCT FROM t.disc_number)
+              AND ((p.track_number = t.track_number AND COALESCE(p.disc_number, 1) = COALESCE(t.disc_number, 1))
                    OR lower(p.title) = lower(t.title))))::int AS uncovered_missing
   FROM albums a
   JOIN tracks t ON t.album_id = a.id