Fix ConnectionClosedError raised from websockets library

[euri10]

Fixes #757

This looks right to me but I'm not a ws expert by any means, previous behaviour was calling the parent connection_lost even if the transport is not in a closing state, which I added, seems like it's ok

This said, given #760 , if some affected users could gently test this PR if it has any unwanted side-effects that would be cool, /poke https://github.com/stefanw and https://github.com/oTree-org

[oTree-org]

Hi @euri10 sorry! I just saw this (I didn't get the notification). I installed your branch but unfortunately I am getting the same traceback as before:

WARNING Error in opening handshake
Traceback (most recent call last):
  File "c:\otree\ve38\lib\site-packages\websockets\server.py", line 130, in handler
    path = await self.handshake(
  File "c:\otree\ve38\lib\site-packages\websockets\server.py", line 586, in handshake
    self.connection_open()
  File "c:\otree\ve38\lib\site-packages\websockets\protocol.py", line 328, in connection_open
    assert self.state is State.CONNECTING
AssertionError
WARNING Error in opening handshake
Traceback (most recent call last):
  File "c:\otree\ve38\lib\site-packages\websockets\server.py", line 130, in handler
    path = await self.handshake(
  File "c:\otree\ve38\lib\site-packages\websockets\server.py", line 586, in handshake
    self.connection_open()
  File "c:\otree\ve38\lib\site-packages\websockets\protocol.py", line 328, in connection_open
    assert self.state is State.CONNECTING
AssertionError
WARNING Error in opening handshake
Traceback (most recent call last):
  File "c:\otree\ve38\lib\site-packages\websockets\server.py", line 130, in handler
    path = await self.handshake(
  File "c:\otree\ve38\lib\site-packages\websockets\server.py", line 586, in handshake
    self.connection_open()
  File "c:\otree\ve38\lib\site-packages\websockets\protocol.py", line 328, in connection_open
    assert self.state is State.CONNECTING
AssertionError
ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "c:\otree\ve38\lib\site-packages\uvicorn\protocols\websockets\websockets_impl.py", line 157, in run_asgi
    result = await self.app(self.scope, self.asgi_receive, self.asgi_send)
  File "c:\otree\ve38\lib\site-packages\uvicorn\middleware\proxy_headers.py", line 45, in __call__
    return await self.app(scope, receive, send)
  File "c:\otree\ve38\lib\site-packages\uvicorn\middleware\asgi2.py", line 7, in __call__
    await instance(receive, send)
  File "c:\otree\core\channels\sessions.py", line 183, in __call__
    return await self.inner(receive, self.send)
  File "c:\otree\core\channels\middleware.py", line 41, in coroutine_call
    await inner_instance(receive, send)
  File "c:\otree\core\channels\consumer.py", line 58, in __call__
    await await_many_dispatch(
  File "c:\otree\core\channels\utils.py", line 51, in await_many_dispatch
    await dispatch(result)
  File "c:\otree\core\channels\consumer.py", line 73, in dispatch
    await handler(message)
  File "c:\otree\core\channels\generic\websocket.py", line 175, in websocket_connect
    await self.connect()
  File "c:\otree\core\otree\channels\consumers.py", line 100, in connect
    await self.post_connect(**self.cleaned_kwargs)
  File "c:\otree\core\otree\channels\consumers.py", line 306, in post_connect
    await self.auto_advanced()
  File "c:\otree\core\otree\channels\consumers.py", line 309, in auto_advanced
    await self.send_json({'auto_advanced': True})
  File "c:\otree\core\channels\generic\websocket.py", line 273, in send_json
    await super().send(text_data=await self.encode_json(content), close=close)
  File "c:\otree\core\channels\generic\websocket.py", line 211, in send
    await super().send({"type": "websocket.send", "text": text_data})
  File "c:\otree\core\channels\consumer.py", line 81, in send
    await self.base_send(message)
  File "c:\otree\core\channels\sessions.py", line 236, in send
    return await self.real_send(message)
  File "c:\otree\ve38\lib\site-packages\uvicorn\protocols\websockets\websockets_impl.py", line 218, in asgi_send
    await self.send(data)
  File "c:\otree\ve38\lib\site-packages\websockets\protocol.py", line 555, in send
    await self.ensure_open()
  File "c:\otree\ve38\lib\site-packages\websockets\protocol.py", line 803, in ensure_open
    raise self.connection_closed_exc()
websockets.exceptions.ConnectionClosedError: code = 1006 (connection closed abnormally [internal]), no reason

Thank you and let me know if I can provide any more info!

[euri10]

ok I'm going to close this if this doesnt fix it, I'm afraid I'm out of ideas as to what's happening

[oTree-org]

OK no problem, thank you for your help :)