fix: store and scrobble with real album artist info string

db/db.go

@@ -9,7 +9,6 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
-	"sort"
 	"strings"
 	"time"
 
@@ -307,6 +306,7 @@ type Album struct {
 	Cover          string    `sql:"default: null"`
 	Artists        []*Artist `gorm:"many2many:album_artists"`
 	TagTitle       string    `sql:"default: null"`
+	TagAlbumArtist string    // display purposes only
 	TagTitleUDec   string    `sql:"default: null"`
 	TagBrainzID    string    `sql:"default: null"`
 	TagYear        int       `sql:"default: null"`
@@ -333,18 +333,6 @@ func (a *Album) IndexRightPath() string {
 	return a.RightPath
 }
 
-func (a *Album) ArtistsStrings() []string {
-	artists := append([]*Artist(nil), a.Artists...)
-	sort.Slice(artists, func(i, j int) bool {
-		return artists[i].ID < artists[j].ID
-	})
-	strs := make([]string, 0, len(artists))
-	for _, artist := range artists {
-		strs = append(strs, artist.Name)
-	}
-	return strs
-}
-
 type PlayQueue struct {
 	ID        int `gorm:"primary_key"`
 	CreatedAt time.Time

db/migrations.go

@@ -66,6 +66,7 @@ func (db *DB) Migrate(ctx MigrationContext) error {
 		construct(ctx, "202309070009", migrateDeleteArtistCoverField),
 		construct(ctx, "202309131743", migrateArtistInfo),
 		construct(ctx, "202309161411", migratePlaylistsPaths),
+		construct(ctx, "202310252205", migrateAlbumTagArtistString),
 	}
 
 	return gormigrate.
@@ -729,3 +730,7 @@ func backupDBPre016(tx *gorm.DB, ctx MigrationContext) error {
 	}
 	return Dump(context.Background(), tx, fmt.Sprintf("%s.%d.bak", ctx.DBPath, time.Now().Unix()))
 }
+
+func migrateAlbumTagArtistString(tx *gorm.DB, _ MigrationContext) error {
+	return tx.AutoMigrate(Album{}).Error
+}

scanner/scanner.go

@@ -372,6 +372,7 @@ func populateAlbum(tx *db.DB, album *db.Album, trags tagcommon.Info, modTime tim
 	albumName := tagcommon.MustAlbum(trags)
 	album.TagTitle = albumName
 	album.TagTitleUDec = decoded(albumName)
+	album.TagAlbumArtist = tagcommon.MustAlbumArtist(trags)
 	album.TagBrainzID = trags.AlbumBrainzID()
 	album.TagYear = trags.Year()
 
@@ -381,7 +382,6 @@ func populateAlbum(tx *db.DB, album *db.Album, trags tagcommon.Info, modTime tim
 	if err := tx.Save(&album).Error; err != nil {
 		return fmt.Errorf("saving album: %w", err)
 	}
-
 	return nil
 }
 

server/ctrlsubsonic/handlers_common.go

@@ -7,6 +7,7 @@ import (
 	"math"
 	"net/http"
 	"path/filepath"
+	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -71,7 +72,7 @@ func (c *Controller) ServeScrobble(r *http.Request) *spec.Response {
 		scrobbleTrack.Track = track.TagTitle
 		scrobbleTrack.Artist = track.TagTrackArtist
 		scrobbleTrack.Album = track.Album.TagTitle
-		scrobbleTrack.AlbumArtist = strings.Join(track.Album.ArtistsStrings(), ", ")
+		scrobbleTrack.AlbumArtist = albumArtistString(track.Album)
 		scrobbleTrack.TrackNumber = uint(track.TagTrackNumber)
 		scrobbleTrack.Duration = time.Second * time.Duration(track.Length)
 		if _, err := uuid.Parse(track.TagBrainzID); err == nil {
@@ -513,3 +514,21 @@ func lowerUDecOrHash(in string) string {
 	}
 	return string(lower)
 }
+
+// not everyone's records may have the album.TagAlbumArtist column set, since we didn't always store that.
+// try it first, but fallback to a list from the artists table
+func albumArtistString(album *db.Album) string {
+	if album.TagAlbumArtist != "" {
+		return album.TagAlbumArtist
+	}
+
+	artists := append([]*db.Artist(nil), album.Artists...)
+	sort.Slice(artists, func(i, j int) bool {
+		return artists[i].ID < artists[j].ID
+	})
+	names := make([]string, 0, len(artists))
+	for _, artist := range artists {
+		names = append(names, artist.Name)
+	}
+	return strings.Join(names, ", ")
+}