Native (non-Docker) installs launched uvicorn without --loop asyncio, so
uvicorn[standard] auto-selected uvloop. uvloop's SSL layer drops
already-received but still-buffered data when the client closes the data
connection without a TLS close_notify while the reader is flow-control
paused on slow storage. cmd_STOR writes each chunk to disk inside the read
loop, so a slow consumer falls behind, the tail is lost, read() returns a
clean EOF, and the loop exits with no exception -- the server acked 226 for
a file it truncated itself, then archived, queued, and forwarded the corrupt
3MF to the real printer.
Fix in two independent layers:
1. Remove the trigger: add --loop asyncio to every native launch path,
matching the Dockerfile -- deploy/bambuddy.service, install/install.sh
(systemd + launchd), spoolbuddy/install/install.sh, the Windows NSSM
service, README, CONTRIBUTING dev command.
2. Defense in depth (loop-independent): cmd_STOR now validates that a
received .3mf opens as a ZIP (reads the central directory, no
decompression) before replying 226. A truncated/corrupt file is dropped
and answered with 426, and on_file_received never runs -- so a broken
upload surfaces as an immediate slicer-side send error instead of being
archived and pushed to the printer. Scoped to .3mf; other filetypes pass
through unchanged.
maziggy