Four George Harrison albums would not play from a MyQBZ collection:
ambiguous id "5099951336752" (Some(Album)):
candidates [SourceId("qobuz"), SourceId("subsonic")];
caller must supply a source
The caller HAD supplied one. The MyQBZ row stores `source = 'qobuz'` and
`RawRef::from_mixtape_item` threads it through correctly; nothing about
the storage or the call chain was wrong. The bug is that
`SubsonicSource::recognises` ORed a namespace-bit test ON TOP of the
source word, so it claimed an id it can never own while Qobuz claimed it
legitimately — two hits, and `claim` refuses to guess.
`5099951336752` is an EAN-13 barcode (EMI/Parlophone, "Somewhere In
England"). Checked arithmetically rather than assumed: bit 42 set,
nothing above the payload mask — exactly `RemoteSource::of_id`'s Subsonic
predicate. The reserved band is 4_398_046_511_104 ..= 5_497_558_138_879,
i.e. EVERY 13-digit barcode from 4398… to 5497…, which is all of
EMI/Parlophone's 5099… prefix. That is why four albums failed together
and why it is deterministic per album rather than flaky.
Two gates, applied to all three cached sources:
- An explicit and DIFFERENT source word now returns false outright. A
bit pattern must never outvote a caller who already said what this
is.
- A namespaced numeric is a TRACK rowid by construction, so the arm no
longer fires in ALBUM position at all. That is the narrower and more
honest statement, and on its own it would have spared this barcode.
Plex needed the same edit and not as tidying: its arm is the loosest of
the three (a bare bit test, no payload bound) and its Album branch
answers `Err(BadIdShape)`, which the registry propagates AHEAD of any
tiebreak — so a barcode with bit 40 set failed with a confusing *Plex*
error on an id Plex never owned.
WHY THIS WAS NEVER CAUGHT: every disjointness test used the barcode
"0060254702523", whose LEADING ZERO puts it below all three floors, so
the entire in-band class was untested. The new test uses the real id and
asserts up front that it still sits in the band, so it cannot quietly
stop covering the case. Verified the honest way — with the old predicate
restored the new test FAILS, with the fix it passes; 90 tests green, and
`namespace_bit_is_enough_to_recognise_without_a_source_word` (the Plex
mixtape-track case that must not regress) stays green.
cc
vicrodh
d40fbb36d2