bug#16034: 24.3.50; scrolling is very long to happen or never happen

[Eli Zaretskii]

> From: Thierry Volpiatto <thierry.volpiatto@gmail.com>
> Date: Tue, 03 Dec 2013 11:58:39 +0100
> 
> Thierry Volpiatto <thierry.volpiatto@gmail.com> writes:
> 
> > Eli Zaretskii <eliz@gnu.org> writes:
> >
> >>> From: Thierry Volpiatto <thierry.volpiatto@gmail.com>
> >>> Date: Tue, 03 Dec 2013 10:26:19 +0100
> >>> 
> >>> 1) Go to scratch buffer
> >>> 
> >>> 2) `switch-to-buffer-other-window' in a consequent buffer
> >>
> >> What do you mean by "consequent buffer"?
> >
> > Use a buffer that is longer enough to scroll (i.e in emacs -Q *Messages*
> > is not long enough to be scrolled)
> >
> >> Is this in "emacs -Q" or in a session that has other buffers besides
> >> *scratch* and *Messages*?
> >
> > In both.
> 
> To make this happen faster, you can repeat the recipe I sent, then when
> you see nothing happen, hit `C-x o', the window is immediately scrolled.

If I evaluate the expression via "M-:", I don't see any problem, the
other buffer is scrolled immediately.

I still am not sure I did what you meant me to do (rant: why is it
that some Emacs developers don't bother to post detailed enough
recipes that spell everything out and leave no t's uncrossed?).
Here's what I did:

  emacs -Q
  C-x C-f src/xdisp.c RET
  C-x 4 b *scratch* RET
  M-: (with-selected-window (next-window) (scroll-up 12)) RET

This scrolls immediately.

Perhaps you meant to type the expression in *scratch* and evaluate it
with C-j or C-x C-e?  If so, I can indeed confirm that the scroll
doesn't happen in that case.  I'm guessing this is due to the latest
Stefan's changes, because in an older build I don't see this.