bug#70386: 30.0.50; (recenter 0 t) does not put point on top of the window

[Eli Zaretskii <eliz@gnu.org>]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: Po Lu <luangruo@yahoo.com>, 70386@debbugs.gnu.org
> Date: Mon, 15 Apr 2024 17:13:39 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> Observed:
> >> 
> >> 1. Line at point slowly scrolls up until it reaches top of the window
> >> (`pixel-scroll-precision-interpolate' call)
> >> 
> >> 2. Line at point is reset back to its initial scroll position
> >>    (`recenter' call)
> >
> > What is the "initial scroll position" in this case?
> 
> The position before M-x eval-buffer
> 
> In other words, the window slowly scrolls up, moving the point to the
> top, but then quickly resets back to how it looked like before the
> scroll started.

No, it does not, at least not on my system.  There's a small vscroll
(you should see it if you move the cursor vertically with C-p after
eval-buffer returns).  So the code works, it just yields a vscroll
that is not what you expect for some reason (and in about 50% of my
attempts -- in the rest the code works as you expect).