On macOS (256 soft fd limit), routing the weixin/email pollers through a
local HTTP proxy leaked one TCP socket per failed poll/connect cycle
until the gateway hit `[Errno 24] Too many open files` and crashed
(launchd respawn loop). Live capture showed 216 of 256 fds pinned on
connections to the proxy, ~214 of them abandoned.
Code-side gaps fixed:
- email adapter, `connect()`: no try/finally around the IMAP test
connection — a failure in login/ID/select/search abandoned the
connected socket with no owner. Every reconnect-watcher retry builds
a fresh adapter, so each retry against an unreachable/proxied host
leaked another fd. Teardown now runs in `finally`.
- email adapter, IMAP teardown: `imaplib.IMAP4.logout()` only swallows
`OSError` internally; on a broken connection `LOGOUT` raises
`IMAP4.abort` before the internal `shutdown()`, leaving the socket
open. New `_close_imap()` helper chases a failed `logout()` with an
unconditional `shutdown()`; used in `connect()` and
`_fetch_new_messages()`.
- weixin adapter: repeated poll failures through a proxy strand
sockets in the aiohttp connector where the tight keepalive reaper
never sees them. The poll loop now recycles its ClientSession
(swap-then-close, safe for concurrent `_process_message` tasks)
after each MAX_CONSECUTIVE_FAILURES streak, tearing down the
connector and every socket it holds.
Targeted tests: tests/gateway/test_poller_fd_lifecycle.py (9 tests).
Reported by @EthanHunter1229 with measured fd captures.
480342232a