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

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: 38457@debbugs.gnu.org
> Date: Fri, 20 Dec 2019 00:52:38 +0200
> 
> This patch now makes easy to implement message stacking that solves the
> issue of several successive calls to message resulting in the user only
> seeing the last message.  This problem was raised many times, and now
> with a function consisting of 12 lines of code attached below, such
> messages are never lost anymore.

Not sure I understand how this will work in practice, UX-wise.  Will
the mini-window be resized to show several lines of messages?  If so,
did you try this with resize-mini-windows set to nil?

> It's eyebrow-raising how many messages were missed before.
> For example, on startup now it shows 3 lines of messages
> I've never seen before:
> 
>   Desktop: 1 frame, 19 buffers restored.
>   15.095076566 seconds
>   Package cl is deprecated

I guess people who have many things happen at startup will like this
feature.  But I'm not sure we should enable this by default in Emacs
27.  WDYT?

> (defcustom messages-stack-timout 2
                            ^^^^^^
"timeout"