Re: master 616da8fa8e: Merge branch 'feature/fix-the-long-lines-display-bug'

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org,  gregory@heytings.org
> Date: Thu, 21 Jul 2022 21:13:26 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Read the code ;-)
> 
> I think it would be more useful to explain what the user can (and can
> not) expect from those "specific optimizations".  Otherwise, it is not
> possible to make an intelligent decision about the value of that option.
> 
> For example, describing that vertical-motion is still slow when point is
> on a long line would be very helpful.
> 
> If that isn't possible, then it would be good to at least explain that
> the optimization (note the singular case) is temporary narrowing of the
> buffer during redisplay.

It's WIP.  It's too early to describe it in such detail, because we
don't yet know the details ourselves.  And even if we knew, the doc
string is probably not a good place for those technicalities.  A doc
string for a variable such as this one should speak in terms
understandable by users who aren't redisplay experts.

When we know exactly what this does, we should revisit this doc string
and see if anything should be done about it.  Meanwhile, I made small
adjustments in the wording.