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

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: stephen.berman@gmx.net,  38457@debbugs.gnu.org
> Date: Wed, 04 Dec 2019 01:44:57 +0200
> 
> > So please try to find a simpler fix for this problem, one that doesn't
> > involve a timer.
> 
> This is the simplest and the safest solution.

The simplest solution would be to prevent dabbrev-expand from
displaying the message in the first place; there are conditions for
that which evidently the new implementation somehow triggers.

> I wanted to implement it earlier but had no time before.  I see no
> problems with it.

Let's not rock the boat too much so close to the release cycle because
of a very minor problem which caused these changes.  You may not see
any problems with it now, but I'm certain we will bump into numerous
problems very soon if we make such significant changes in this
infrastructure, which is used everywhere in Emacs.