Re: Redisplay resets vscroll when window start changes

[Eli Zaretskii]

On November 17, 2021 6:31:32 AM GMT+02:00, Po Lu <luangruo@yahoo.com> wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > My suggestion is to implement equivalents of C-n/C-p that do what you
> > want, instead of asking for previous/next-line to be able to preserve
> > the vscroll, because those commands aren't supposed to support the use
> > case you want to support.
> 
> Yes, I understand that.  But the problem is any command that can call
> `line-move' will end up resetting the vscroll, which most people don't
> expect.  Since making `line-move' not reset the vscroll is not an
> option, a better solution will have to be found, which replacing
> previous-line/next-line is not.


My point is precisely that line-move should not be used for this purpose, 
because it and the other 2 functions it calls don't support this use case, and 
OTOH include a lot of code logic which implicitly assumes a very different use 
case.  It would be much easier and cleaner to implement what you need from 
scratch.