Add transport.is_closing() guard before send in websockets implementation#2861
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hrv-dys wants to merge 5 commits intoKludex:mainfrom
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Add transport.is_closing() guard before send in websockets implementation#2861hrv-dys wants to merge 5 commits intoKludex:mainfrom
hrv-dys wants to merge 5 commits intoKludex:mainfrom
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…tion The websockets_impl.py asgi_send method was missing a check for whether the transport is closing before writing data. Both wsproto_impl.py and websockets_sansio_impl.py already have this guard. Without it, a write to a closing transport can raise an unexpected exception or silently fail. This adds the same is_closing() check, raising ClientDisconnected to give the ASGI app a clean signal that the connection is gone.
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Summary
The
websockets_impl.pyasgi_sendmethod writes data viaawait self.send()without first checking whether the transport is closing. The other two
WebSocket implementations —
wsproto_impl.pyandwebsockets_sansio_impl.py— both guard their writes with
self.transport.is_closing()checks.Without this guard, a write to a closing transport can raise an unexpected
exception inside the websockets library, or silently fail. This fix adds the
same check, raising
ClientDisconnectedto give the ASGI app a clean signalthat the connection is gone.
Belief that guided this fix: the three WebSocket implementations
(websockets, wsproto, websockets-sansio) handle protocol states differently,
so you can't assume they'll all behave the same without explicit guards.
Finding this inconsistency between implementations was only possible by
cross-referencing all three side by side.
Test plan
tests/protocols/test_websocket.pypasses