bug#38457: 27.0.50; dabbrev-expand regression due to message change

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: Eli Zaretskii <eliz@gnu.org>,  38457@debbugs.gnu.org,
>   stephen.berman@gmx.net
> Date: Fri, 06 Dec 2019 02:06:30 +0200
> 
> > I think the regression Stephen noticed is more widespread than just
> > dabbrev-expand: e.g. TRAMP is also affected[1].
> 
> I know that TRAMP is affected.  I had no time to address this before, sorry,
> but now this is fixed by the previous patch I sent 3 days ago that uses a 
> timer.

We need to fix this without a timer, and we need to fix this before
the emacs-27 branch is cut.

One possibility is for 'message' to bind 'minibuffer-message-timeout'
to zero when it calls 'minibuffer-message'.  Would this work in all
the use cases discovered to day?

Thanks.