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

[Eli Zaretskii]

> Date: Thu, 12 Dec 2019 12:33:09 +0800
> From: HaiJun Zhang <netjune@outlook.com>
> Cc: monnier@iro.umontreal.ca, 38457@debbugs.gnu.org, juri@linkov.net
> 
>  (And I don't understand why we are arguing, since you just said in
>  another message that you liked my proposal…) 
> 
> Yes. I like your proposal that message do these things internally. Because 
> the input prompt should always be
> considered, so all these things can be done in ‘message’. Then it seems that 
> we don’t need another api(like
> minibuffer-message)?
> 
> Is the UI of your proposal like this?
> (1) Display combination of the prompt and the message with no timeout.
> (2) If user inputs something, the message is cleared and only prompt is 
> displayed.

Yes.

> The last question: 
> What is the use of minibuffer-message-timeout. It is defined in C. When does 
> it take effect?

It affects how long minibuffer-message waits before removing the
message text, if there are no input events.  Any input event removes
the message even if the timeout didn't expire.