Re: Scrolling commands and skipping redisplay, was: Re: emacs rendering comparisson between emacs23 and emacs26.3

[Eli Zaretskii]

> From: Stefan Monnier <address@hidden>
> Date: Fri, 10 Apr 2020 10:45:08 -0400
> Cc: address@hidden, address@hidden, address@hidden, address@hidden,
>  address@hidden, Eli Zaretskii <address@hidden>
> 
> And in theory it should be possible to make something like
> (setq jit-lock-defer-mode 0) avoid this flicker because the last
> repetition of `C-v` is executed with `input-pending-p` returning nil, so
> we should be able to fully jit-lock right away with no deferral at
> that point.

Redisplay is not instantaneous, so even if you check at some point
through redisplay and find that no input is pending, this can change
while redisplay is in progress.

In any case, this talk about checking whether input is available seems
to mean we want to resurrect the nil value of redisplay-dont-pause,
doesn't it?