bug#40248: 27.0.90; Failure open .authinfo.gpg from Gnus

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Juan José García-Ripoll
>  <juanjose.garcia.ripoll@csic.es>,
>   40248@debbugs.gnu.org
> Date: Sat, 28 Mar 2020 09:40:12 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Lars, can you or someone of the Gnus team tell why
> > nnimap-open-connection-1 binds coding-system-for-* to 'binary?  I
> > don't understand the rationale, as the code which uses this connection
> > seems to expect ASCII text in response.
> 
> The IMAP connections (as do most network protocols) operate on octets,
> not ASCII.

But then only the encoding of the network process started by
nnimap-open-connection-1 should be made no-conversion.  By contrast,
binding coding-system-for-* around the call to open-network-stream has
much wider consequences, as it affects _any_ code run as part of
open-network-stream, in particularly epg-find-configuration, which has
nothing to do with the network stream.  nnimap-open-connection-1 is a
large function, so that binding affects quite a lot more than just the
network process it creates.