Re: MPS: Win64 testers?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 22 Aug 2024 17:51:38 +0000
> From: Pip Cet <pipcet@protonmail.com>
> Cc: Quang Kien Nguyen <kien.n.quang@gmail.com>, Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org, Ihor Radchenko <yantar92@posteo.net>
> 
> > I was running this version today:
> >
> > https://github.com/kiennq/emacs-build/releases/tag/v31.305.20240819.4794ea5
> >
> > Had two different crashes, hope that these backtraces are more useful
> > (thanks again to Pip and Ihor for their help)
> 
> Thank you, that's very useful.  Indeed, it looks like the
> Windows-specific code hands off a pointer to MPS-managed memory to
> GNUTLS to use as a cookie, while other OSes use an FD number cast to an
> intptr_t cast to void *.

You are talking about this line in emacs_gnutls_pull:

  emacs_gnutls_transport_set_errno (process->gnutls_state,
                                    errno == EWOULDBLOCK ? EAGAIN : errno);

which causes us to call GnuTLS thusly:

  gnutls_transport_set_errno (state, err);

is that right?  Does this mean we will have to audit all our calls to
external libraries and make sure we never pass to them any part of any
Lisp object?  That's a tough requirement; it's very easy to miss some
such use, which then triggers segfaults.  Am I missing something?

Btw, I tried using EWW in my MinGW MPS build, and it didn't crash.  Is
it possible to have a reproducible recipe for this?