Re: Redisplay resets vscroll when window start changes

[Stefan Monnier]

Eli Zaretskii [2021-11-19 09:13:53] wrote:
> The current code is not prepared to deal with test cases like that
> one.  The current Emacs code never sets vscroll unless we are moving
> through a tall line, so resetting vscroll as part of previous-line is
> a no-op when there's no tall lines in sight, and is not doing any
> harm.  The test case was produced by a feature not yet in Emacs, and
> so I'm saying that such a feature needs its own variant of
> previous-line.

But to the extent than this feature does not intend to change the
behavior of `previous-line`, this new variant of `previous-line` should
ideally do everything exactly like the current `previous-line`, except
be more careful not to reset vscroll, right?

So, ideally this new version could also be used when that new feature
isn't used?


        Stefan