A disc is the one medium QBZ can play that leaves nothing behind: no path, no
row, no file. Everything learned about it was thrown away when the tray opened
and re-derived from the network next time.
That is fine for names that came from MusicBrainz and not fine for names that
came from a human. One DiscID can name several pressings — this album answers
with four — so the moment there is a button to pick the right one, or a wizard
that lets a title be fixed before it is written, the choice has to outlive the
eject. Otherwise correcting a disc is a toy: fix it, take it out, put it back,
it is wrong again.
A CACHE, not a second source of truth, with one rule that makes it safe: a row
the user edited is never overwritten by an automatic lookup. put_auto refuses
to touch an edited row and only put_user can replace one, enforced in the store
rather than at the call sites so a future third lookup path cannot forget.
Identity is the TOC fingerprint: pure geometry, no network, available before
anything has been looked up, and identical on both platforms. It names the
GEOMETRY rather than the pressing, which is the point — "for this geometry the
user chose pressing 2" is the fact worth keeping.
Global rather than per-user, because which record is in the drive does not
depend on who is logged in. Seven tests, including the one this exists for.
disc_identity carries WHICH disc is open for the two features that name the
medium rather than the session; nothing there persists.
cc
vicrodh
57ae465668