The /track/getList endpoint caps at 50 IDs per call. Sending more in a
single POST either errors out or silently truncates, both of which take
the entire call site down.
For QConnect this surfaced as: pushing a >50-track playlist from the
Qobuz Android app to QBZ caused the materialization step (corebridge
get_tracks_batch hydration) to return an error, abort, and leave only
the 1-track placeholder queue from the earlier align-cursor pass. The
visible symptom was "only the first track loads on Connect playlists
above 50 tracks".
The fix is at the helper level rather than in QConnect: split inputs
larger than 50 into 50-ID windows fetched serially, preserve input
order in the returned Vec. Single-window path is unchanged for the
common case. Same return shape, same error type, so the four call
sites (corebridge.materialize_remote_queue, qbzd qconnect, V2
v2_get_tracks_batch, qbzd catalog) all benefit transparently without
edits to QConnect orchestration code (auto-advance, deletion timing,
queue ordering are untouched).
Serial loop instead of the concurrent fan-out used by get_playlist —
lower risk for the first fix; if QConnect playlists of 200+ tracks
start feeling slow we can revisit with try_join_all.
cc