Multi-disc (#927): capture real disc number at media-server scan time

Every library track was stored with disc_number=1 because the Jellyfin/Plex/Navidrome scan parsed the track number but never the disc field. Multi-disc albums collapsed onto disc 1, so disc-2+ tracks were mis-filed (shown under disc 1) and flagged 'missing' — the frontend title-fallback band-aid couldn't recover it (breaks on iTunes title mismatches).

Now the shared insert_or_update_media_track reads the disc number (Jellyfin .discNumber=ParentIndexNumber, Navidrome .discNumber, Plex .parentIndex), floors to >=1, and stores it in the INSERT + UPDATE. The disc_number column is ensured on init (it was only added by a migration that doesn't run on fresh installs, so the new INSERT would have hard-failed for new users). The enhanced album view already carries disc_number through (SELECT * -> dict), so the display fixes itself once the column is populated — a re-scan backfills existing libraries. Seam-tested across Jellyfin/Navidrome/Plex shapes + the floor-to-1 + re-scan-update cases.

core/jellyfin_client.py

@@ -105,6 +105,7 @@ class JellyfinTrack:
         self.title = jellyfin_data.get('Name', 'Unknown Track')
         self.duration = jellyfin_data.get('RunTimeTicks', 0) // 10000  # Convert from ticks to milliseconds
         self.trackNumber = jellyfin_data.get('IndexNumber')
+        self.discNumber = jellyfin_data.get('ParentIndexNumber')  # multi-disc: disc number
         self.year = jellyfin_data.get('ProductionYear')
         self.userRating = jellyfin_data.get('UserData', {}).get('Rating')
         self.addedAt = self._parse_date(jellyfin_data.get('DateCreated'))

core/navidrome_client.py

@@ -110,6 +110,7 @@ class NavidromeTrack:
         self.title = navidrome_data.get('title', 'Unknown Track')
         self.duration = navidrome_data.get('duration', 0) * 1000  # Convert to milliseconds
         self.trackNumber = navidrome_data.get('track')
+        self.discNumber = navidrome_data.get('discNumber')  # multi-disc: disc number
         self.year = navidrome_data.get('year')
         self.userRating = navidrome_data.get('userRating')
         self.addedAt = self._parse_date(navidrome_data.get('created'))

database/music_database.py

@@ -1171,6 +1171,13 @@ class MusicDatabase:
             if track_cols and 'year' not in track_cols:
                 cursor.execute("ALTER TABLE tracks ADD COLUMN year INTEGER")
                 logger.info("Repaired missing year column on tracks table (#910)")
+            # #927 — multi-disc fix: the scan now writes a real disc_number, but the column
+            # was only ever added by a separate migration that doesn't run on fresh installs,
+            # so the new INSERT/UPDATE would hard-fail with "no column named disc_number".
+            # Same shape as the year repair above: additive, defaults to 1, ensured on every DB.
+            if track_cols and 'disc_number' not in track_cols:
+                cursor.execute("ALTER TABLE tracks ADD COLUMN disc_number INTEGER DEFAULT 1")
+                logger.info("Repaired missing disc_number column on tracks table (#927)")
 
             cursor.execute("PRAGMA table_info(albums)")
             album_cols = {c[1] for c in cursor.fetchall()}
@@ -6635,6 +6642,19 @@ class MusicDatabase:
                 track_id = str(track_obj.ratingKey)
                 title = track_obj.title
                 track_number = getattr(track_obj, 'trackNumber', None)
+                # Multi-disc: capture the disc number so multi-disc albums don't all
+                # collapse onto disc 1 (which mis-files disc-2+ tracks and flags them
+                # "missing"). Jellyfin/Navidrome wrappers set .discNumber; plexapi's Track
+                # exposes .parentIndex. Floor to >=1 — a missing/0 disc is disc 1.
+                _raw_disc = getattr(track_obj, 'discNumber', None)
+                if _raw_disc is None:
+                    _raw_disc = getattr(track_obj, 'parentIndex', None)
+                try:
+                    disc_number = int(_raw_disc)
+                    if disc_number < 1:
+                        disc_number = 1
+                except (TypeError, ValueError):
+                    disc_number = 1
                 duration = getattr(track_obj, 'duration', None)
                 
                 # Get file path and media info (Plex-specific, Jellyfin may not have these)
@@ -6726,9 +6746,9 @@ class MusicDatabase:
                 if is_new_track:
                     cursor.execute("""
                         INSERT INTO tracks
-                        (id, album_id, artist_id, title, track_number, duration, file_path, bitrate, file_size, server_source, track_artist, musicbrainz_recording_id, updated_at)
-                        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, CURRENT_TIMESTAMP)
-                    """, (track_id, album_id, artist_id, title, track_number, duration, file_path, bitrate, file_size, server_source, track_artist, mbid))
+                        (id, album_id, artist_id, title, track_number, disc_number, duration, file_path, bitrate, file_size, server_source, track_artist, musicbrainz_recording_id, updated_at)
+                        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, CURRENT_TIMESTAMP)
+                    """, (track_id, album_id, artist_id, title, track_number, disc_number, duration, file_path, bitrate, file_size, server_source, track_artist, mbid))
                 else:
                     # Update server-provided fields only — preserves spotify_track_id, deezer_id,
                     # isrc, bpm, and all other enrichment data. file_size uses
@@ -6737,7 +6757,7 @@ class MusicDatabase:
                     # an existing value.
                     cursor.execute("""
                         UPDATE tracks
-                        SET album_id = ?, artist_id = ?, title = ?, track_number = ?,
+                        SET album_id = ?, artist_id = ?, title = ?, track_number = ?, disc_number = ?,
                             duration = ?, file_path = ?, bitrate = ?,
                             file_size = COALESCE(?, file_size),
                             server_source = ?,
@@ -6745,7 +6765,7 @@ class MusicDatabase:
                             musicbrainz_recording_id = COALESCE(?, musicbrainz_recording_id),
                             updated_at = CURRENT_TIMESTAMP
                         WHERE id = ?
-                    """, (album_id, artist_id, title, track_number, duration, file_path, bitrate, file_size, server_source, track_artist, mbid, track_id))
+                    """, (album_id, artist_id, title, track_number, disc_number, duration, file_path, bitrate, file_size, server_source, track_artist, mbid, track_id))
 
                 conn.commit()
 

tests/test_media_track_disc_number.py

@@ -0,0 +1,68 @@
+"""Multi-disc fix (#927): the media-server scan must store the real disc number.
+
+Every track was stored with disc_number=1 because the Jellyfin/Plex/Navidrome scan never
+read the disc field — so multi-disc albums collapsed onto disc 1, mis-filing disc-2+ tracks
+and flagging them "missing". insert_or_update_media_track now reads the disc number off the
+track object (Jellyfin/Navidrome `.discNumber`, Plex `.parentIndex`), floored to >=1.
+"""
+
+from __future__ import annotations
+
+from types import SimpleNamespace
+
+from database.music_database import MusicDatabase
+
+
+def _db(tmp_path):
+    db = MusicDatabase(database_path=str(tmp_path / "t.db"))
+    with db._get_connection() as c:
+        c.execute("INSERT OR IGNORE INTO artists (id, name) VALUES ('art1', 'Evan Call')")
+        c.execute("INSERT OR IGNORE INTO albums (id, artist_id, title) VALUES ('alb1', 'art1', 'Frieren OST')")
+        c.commit()
+    return db
+
+
+def _track(rating_key, title, track_number, **kw):
+    return SimpleNamespace(ratingKey=rating_key, title=title, trackNumber=track_number,
+                           duration=200000, **kw)
+
+
+def _disc_of(db, track_id):
+    with db._get_connection() as c:
+        row = c.execute("SELECT disc_number, track_number FROM tracks WHERE id = ?", (track_id,)).fetchone()
+    return (row['disc_number'], row['track_number'])
+
+
+def test_jellyfin_navidrome_disc_number_stored(tmp_path):
+    db = _db(tmp_path)
+    # .discNumber is what the Jellyfin (ParentIndexNumber) + Navidrome (discNumber) wrappers set.
+    db.insert_or_update_media_track(_track('t-d2', 'Waltz for Stark and Fern', 34, discNumber=2), 'alb1', 'art1', 'jellyfin')
+    db.insert_or_update_media_track(_track('t-d1', 'The Magic Within', 32, discNumber=1), 'alb1', 'art1', 'jellyfin')
+    assert _disc_of(db, 't-d2') == (2, 34)
+    assert _disc_of(db, 't-d1') == (1, 32)
+
+
+def test_plex_parent_index_used_as_disc(tmp_path):
+    db = _db(tmp_path)
+    # plexapi Track has no .discNumber — disc comes from .parentIndex.
+    db.insert_or_update_media_track(_track('t-plex', 'Disc 2 Track', 5, parentIndex=2), 'alb1', 'art1', 'plex')
+    assert _disc_of(db, 't-plex') == (2, 5)
+
+
+def test_missing_or_bad_disc_floors_to_one(tmp_path):
+    db = _db(tmp_path)
+    db.insert_or_update_media_track(_track('t-none', 'No Disc', 1), 'alb1', 'art1', 'jellyfin')          # no disc attr
+    db.insert_or_update_media_track(_track('t-zero', 'Zero Disc', 2, discNumber=0), 'alb1', 'art1', 'jellyfin')
+    db.insert_or_update_media_track(_track('t-str', 'Junk Disc', 3, discNumber='x'), 'alb1', 'art1', 'jellyfin')
+    assert _disc_of(db, 't-none')[0] == 1
+    assert _disc_of(db, 't-zero')[0] == 1
+    assert _disc_of(db, 't-str')[0] == 1
+
+
+def test_update_path_backfills_disc_on_rescan(tmp_path):
+    db = _db(tmp_path)
+    # First scan (old behavior simulated): no disc -> 1. Re-scan with the real disc -> updated.
+    db.insert_or_update_media_track(_track('t-x', 'Track', 7), 'alb1', 'art1', 'jellyfin')
+    assert _disc_of(db, 't-x') == (1, 7)
+    db.insert_or_update_media_track(_track('t-x', 'Track', 7, discNumber=3), 'alb1', 'art1', 'jellyfin')
+    assert _disc_of(db, 't-x') == (3, 7)