Fix playlist cannot be empty via Subsonic API

persistence/playlist_repository.go

@@ -110,10 +110,10 @@ func (r *playlistRepository) Put(p *model.Playlist) error {
 		return nil
 	}
 	// Only update tracks if they were specified
-	if len(pls.Tracks) == 0 {
-		return nil
+	if len(pls.Tracks) > 0 {
+		return r.updateTracks(id, p.MediaFiles())
 	}
-	return r.updateTracks(id, p.MediaFiles())
+	return r.RefreshStatus(id)
 }
 
 func (r *playlistRepository) Get(id string) (*model.Playlist, error) {

persistence/playlist_track_repository.go

@@ -164,6 +164,18 @@ func (r *playlistTrackRepository) Delete(ids ...string) error {
 	return r.playlistRepo.renumber(r.playlistId)
 }
 
+func (r *playlistTrackRepository) DeleteAll() error {
+	if !r.isTracksEditable() {
+		return rest.ErrPermissionDenied
+	}
+	err := r.delete(Eq{"playlist_id": r.playlistId})
+	if err != nil {
+		return err
+	}
+
+	return r.playlistRepo.renumber(r.playlistId)
+}
+
 func (r *playlistTrackRepository) Reorder(pos int, newPos int) error {
 	if !r.isTracksEditable() {
 		return rest.ErrPermissionDenied