bug#42406: Mouse-wheel scrolling can be flickering

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: alan@idiocy.org,  konrad.podczeck@univie.ac.at,  42406@debbugs.gnu.org
> Date: Fri, 18 Dec 2020 18:12:45 -0500
> 
> Any change to the redisplay will risk introducing regressions because of
> the previous code's intricate workings so if you reject this simple
> change, I can't see why you wouldn't reject similarly any other change
> to the redisplay (including your advocated big redesign).
> 
> After all, my `redisplay` bits did pretty much exactly what you suggest
> we do, except that they did not try to use a finer distinction between
> frametitles, headerlines, modelines, ...
> 
> I really just don't understand your stance here.

My stance is that the problem is minor (I cannot even see it on my
system, so it could well be specific to NS), and thus the change is
unjustified because its benefits are basically nil.

If that same change would motivate a redesign I described, we'd
benefit much more from that, so it would be justified to sustain even
greater risks.