Disc number isn't parsed in playlist

[Anders Honoré]

If I load an album that has several discs under the same album name, I expect Musique to parse this and sort the tracks according to disc number first and track number second like this:

[disc 1]
1 track 1a
2 track 2a
3 track 3a
4 track 4a
[disc 2]
1 track 1b
2 track 2b
3 track 3b
4 track 4b

Instead, it gets parsed like this:

1 track 1a
1 track 1b
2 track 2a
2 track 2b
3 track 3a
3 track 3b
4 track 4a
4 track 4b