bug#36709: Likely bug in scm_port_poll

bug#36709: Likely bug in scm_port_poll

[Mark H Weaver]

I sent the following message about a month ago, and now am forwarding to
bug-guile so that we do not forget about it.

       Mark


From: Mark H Weaver <mhw@netris.org>
Subject: Likely bug in scm_port_poll
Date: Tue, 18 Jun 2019 00:40:27 -0400
Message-ID: <87a7ef1p61.fsf@netris.org>
Cc: guile-devel@gnu.org
To: Andy Wingo <wingo@pobox.com>

Hi Andy,

If you'd be willing to take a quick look at this, I'd be grateful.
Probably a bug, but I feel uneasy that I might be overlooking something.

scm_port_poll contains the following code:

  if (scm_i_string_contains_char (events, 'r'))
    c_events |= POLLIN;
  if (scm_i_string_contains_char (events, '!'))
    c_events |= POLLPRI;
  if (scm_i_string_contains_char (events, 'w'))
    c_events |= POLLIN;

That second POLLIN should be POLLOUT, right?

      Thanks,
        Mark

https://git.savannah.gnu.org/cgit/guile.git/tree/libguile/ports.c?h=stable-2.2&id=420c2632bb1f48e492a035c1d216f209734f45e6#n1423

bug#36709: Likely bug in scm_port_poll

[Ludovic Courtès]

Hi Mark,

Mark H Weaver <mhw@netris.org> skribis:

> If you'd be willing to take a quick look at this, I'd be grateful.
> Probably a bug, but I feel uneasy that I might be overlooking something.
>
> scm_port_poll contains the following code:
>
>   if (scm_i_string_contains_char (events, 'r'))
>     c_events |= POLLIN;
>   if (scm_i_string_contains_char (events, '!'))
>     c_events |= POLLPRI;
>   if (scm_i_string_contains_char (events, 'w'))
>     c_events |= POLLIN;
>
> That second POLLIN should be POLLOUT, right?

I agree.  Clearly it must be a typo, so I’ve pushed the fix as
659526d33b2db1b0924b2769b6a0b824709860cc.

Thanks!

Ludo’.