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

[Dmitry Gutov]

On 10.04.2020 18:36, Eli Zaretskii wrote:
> > > > > Depends on what you mean by "precision".  They might very well miss
> > > > > some parts of the buffer entirely, i.e. never see them on display.
> > > > But that happens regardless of whether the scroll is computed correctly,
> > > > because redisplay itself is skipped.
> > > It isn't skipped here if I use jit-lock-defer-time.
> > I was talking about `fast-but-imprecise-scrolling`
> Now I'm confused: fast-but-imprecise-scrolling doesn't skip redisplay.

Allow me to annotate one of the previous replies:

  regardless of whether the scroll is computed correctly

    (i.e. whether fast-but-imprecise-scrolling is nil or t)

  redisplay itself is skipped.

And it can also be skipped on slow enough machines, even with font-lock 
disabled altogether.