Allow 1st argument $read of stream_select to be nullable

[niconoe-]

Detected on vimeo/psalm#3036.

The documentation allows null here: https://www.php.net/manual/en/function.stream-select.php

[ondrejmirtes]

Can you please show me where the documentation exactly states that? Thank you.

[niconoe-]

I read it in the signature of the function:
it's ?array &$read,, not array &$read,

I also tested it in 3v4l.org: https://3v4l.org/rFifQ

null is actually a valid value for all of the 3 main arguments here. The hitcup is that you can't do the call with the 3 argument to null at the same time, but I guess this is something else not related to the functionMap.

[ondrejmirtes]

Thank you.