Subject: Re: bug#34341: 26.1; url-retrieve-synchronously returns blank buffer

From: Robert Pluim <[email-masked]>
Date: Tue, 07 May 2019 08:35:00 +0200

>>>>> On Mon, 06 May 2019 20:16:52 -0400, Noam Postavsky <[email-masked]> said:

    Noam> Eli Zaretskii <[email-masked]> writes:
    >>> From: Robert Pluim <[email-masked]> Date: Mon, 06 May 2019
    >>> 14:15:27 +0200 Cc: Laurent Charignon <[email-masked]>,
    >>> [email-masked]
    >>> 
    >>> >>>>> On Mon, 06 May 2019 08:10:32 -0400, Noam Postavsky
    >>> <[email-masked]> said:
    >>> 
    Noam> Thanks, I wasn't aware of this, I'll check if that helps
    Noam> later today.  I think it makes sense to backport regardless
    Noam> though.

    Noam> I can confirm that

    Noam>     (setq gnutls-algorithm-priority "NORMAL:-VERS-TLS1.3")

    Noam> avoids the problem on my Arch box (has gnutls v3.6.7).

OK, so itʼs the same issue.

    Noam> I found this smaller change fixes it also.  Is it simple
    Noam> enough to for emacs-26?  Otherwise, we should set
    Noam> gnutls-algorithm-priority because (as far as I understand)
    Noam> we have a broken TLS1.3 implementation at the momement.

If we do decide to disable TLS1.3, which Iʼm not really in favour of,
changing the defaults in lisp/net/gnutls.el:gnutls-boot-parameters
might be better than setting gnutls-algorithm-priority. Iʼd prefer
your gnutls.c patch, although I haven't had a chance to test it yet.

Robert