Re: kern/60786: poll reports socket writable after shutdown(SHUT_WR)

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Fri, 25 Sep 2026 01:24:10 +0000
    From:        Taylor R Campbell <riastradh%NetBSD.org@localhost>
    Message-ID:  <20260925012412.01FC684D78%mail.netbsd.org@localhost>

  | Oops, disregard -- that was a bad test I drafted too quickly.

No problem, and I can certainly believe there are cases where
select/poll aren't woken when they should be, lots has been added
to the kernel since they were first created, and it would be easy
for bugs to have slipped in.

The only reason I replied initially, is because it is too easy to
fall into the rabbit hole of believing that if select/poll say
that an fd can be read/written, it should mean successfully.
It doesn't, and never did - they were just a mechanism (long before
BSD had O_NONBLOCK support in any form) to avoid hanging, and allow
a semblance of fake threading (before that existed either).

kre