bug#21969: VC opens new window to display minimal messages

[Eli Zaretskii]

> Cc: 21969@debbugs.gnu.org, david.reitter@gmail.com
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Sun, 22 Nov 2015 18:45:17 +0200
> 
> On 11/22/2015 06:08 PM, Eli Zaretskii wrote:
> 
> > Why not always show the output in a window, and remove the code that
> > shows it in the echo area?
> 
> Because showing it in a buffer disturbs the window configuration, and 
> you have to press `q' to quit it. Seems reasonable to want to avoid that 
> when there's nothing to show.

How is that different from when Grep doesn't find any hits, or a
compile command produces no output?

IOW, we already have this kind of popping windows elsewhere in Emacs,
so why cannot this use case behave similarly?