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

[Eli Zaretskii]

> Date: Tue, 10 Dec 2019 19:49:00 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 38457@debbugs.gnu.org, juri@linkov.net
> 
> > I guess there could be some visible artifacts of this subterfuge in the
> > case where the minibuffer's content is currently affected by overlays
> > (since we presumably wouldn't copy those to the echo-area), but I'm not
> > sure this would be a real problem.
> 
> We could copy the overlays, if that's important.

Btw, the current code on master also removes the overlays where
icomplete shows the completion candidates.  You can try it:

  . Evaluate:

    (defun my-message ()
      (interactive)
      (message "my most important message"))
    (global-set-key [f5] 'my-message)

  . M-x icomplete-mode RET
  . C-x C-f
  . F5

After "C-x C-f" the list of candidates will be displayed in the
minibuffer; pressing F5 removes the list and shows the message
instead.