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

[martin rudalics]

> This indeed works for the particular snippet I posted. However, I have a
> more complex application where I am already using set-window-point, and
> this does not fix the issue.

All we need to know for why this happens would be the exact sequence
of (window) point and window start settting operations performed by
that application.

> However, in the application for which I need this functionality, it
> works completely as intended if I add (redisplay) between the calls of
> set-window-point and set-window-start.
>
>>From this, I get the impression that a pending redisplay may interfere
> with reliably setting the window-start even if window-point is set!

One more reason to dig further into this.

martin