Don't rebuild HTTP session with no connections

[martindurant]

Fixes #1019

[martindurant]

@Koncopd , latest aiobotocore doesn't like that; but I'm not sure why we are getting an unstarted session the second time around.

[martindurant]

Given that there isn't much cost to "rebuilding" the http_sessions without any actual live sessions, and that it only happens once, I think it's not worth trying to prob aiobotocore in the right direction here. What do you think, @Koncopd ?

[Koncopd]

As I said, my problem is that rebuilding aiobotocore session (not http sessions) erases the credentials I pass. And if I provide a session, it should not happen that I just lose it on set_session.

[Koncopd]

Here I mean

s3fs/s3fs/core.py

Line 643 in 731e125

self.session = aiobotocore.session.AioSession(**self.kwargs)

[Koncopd]

Btw the failing test (test_session_close) looks strange to me, it runs run_program(run) with True and False, but run parameter doesn’t seem to be passed anywhere inside run_program. I assume it just runs the same code, but fails on the second execution only, so the problem is probably due to caching.

[martindurant]

it just runs the same code, but fails on the second execution only

Yes, that is exactly the idea. If I remember, the variable is there to allow a breakpoint in the function, where we know which invocation we are on.

[Koncopd]

Thank you, i will try to check the problem later.