The lazy source-build commit (1ddde12) introduced a race: when the
user taps play on a new track while a previous queue's
_fillRemainingSources is still working, the stale fill keeps
calling _player.addAudioSource() on the new player state — appending
old-playlist tracks into the new queue and confusing the player into
the "locked to one song" symptom.
Fix: queue-generation counter. setQueueFromTracks bumps
_queueGeneration first thing; the background fill captures its gen
at start and aborts before any further player mutation if a newer
queue has taken over. The previous play() never gets to mutate the
new player state.
Also resets _suppressIndexUpdates at the start of every
setQueueFromTracks (defensive — covers the case where a prior
backward-fill bailed on its gen check before reaching `finally`)
and only releases the flag in finally if we're still the active
gen.
Symptoms this should resolve:
- "locked to one song" after rapid play taps
- Late `play() returned 73189ms` lines indicating a previous
hung play() call finally resolving and stepping on current state
- Player stuck in odd processingState after queue swaps
bvandeusen
ab62a3d118