bug#39540: when emacsclient invoked messages left in minibuffer should be swept

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson
>  <jidanni@jidanni.org>
> Date: Mon, 10 Feb 2020 13:45:43 +0800
> 
> If
> "Directory has changed on disk; type g to update Dired"
> is sitting in the minibuffer when one does
> $ emacsclient -n some_file.txt
> that message should be cleared. Instead it is left sitting there,
> even though we are not looking at a dired buffer anymore.
> It should be just like we did C-x C-f...
> emacs-version "26.3"

Please show a complete recipe, starting with invoking the daemon or
the server Emacs.  I don't think I understand the situation well
enough to test it in the current development version (where it might
well have been fixed, as we had several changes in this area).

Thanks.