bug#34038: 26.1; set-window-start sometimes fails to set window start

[Markus Triska]

Eli Zaretskii <eliz@gnu.org> writes:

> Can you describe what you are trying to achieve by using
> set-window-start?  It's somewhat unusual to use that API without also
> moving point accordingly.

I noticed these issues in a larger application, primarily in an attempt
to reliably and fully restore a previous window configuration.

The key issue seems to be that point must be set correctly: If point is
at a position that is known to be displayable with a given window-start,
then if point is again set to that position, set-window-start will also
reliably set window-start to that start. Is this correct?

Personally, I would appreciate some comment regarding such a guarantee,
or the assumptions, in the documentation of set-window-start.