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

[Juri Linkov]

>> 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?

Actually, it works well only when resize-mini-windows is 'grow-only'.

>> 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?

I posted a request for comments on emacs-devel.