I have discovered that the behavior seems to occur on all systems, but
that I forgot to mention another single step, which is that I am
maximizing the Emacs window first, using the GNOME desktop shortcut
(Super + Arrow Up). However, the behavior is the same (i.e. vscroll
does not get set) when using 'M-x toggle-frame-maximized' before
trying the code snippet.

Now, the docstring of 'set-window-vscroll' says:

'PRESERVE-VSCROLL-P makes setting the start of WINDOW preserve the
vscroll if its start is "frozen" due to a resized mini-window.'

I don't really understand what that sentence means, so I am now still
wondering if this behavior could be considered a bug or not.

Should I report this as a bug?

Thanks





On Sun, 5 Nov 2023 at 21:17, dalanicolai <dalanicolai@gmail.com> wrote:

> Hi all,
>
> If there is anybody on Fedora here, could you please try to evaluate the
> code
> from the original message starting from emacs -Q, and afterwards check what
> is the value of
>
> M-: (window-vscroll nil t)
>>
>
> Do you get 0 or 300?
>
> For some reason this does not work here. I have just built emacs from
> `HEAD`
> without using any `configure` flags. It does not work here, neither on
> emacs 28.3, 29.1 or on the latest 30.5.
>
> I have also tried on Ubuntu on another laptop, where the code works fine.
> Would be great if possible.
>
> Thanks!
>
> On Sun, 5 Nov 2023 at 19:14, dalanicolai <dalanicolai@gmail.com> wrote:
>
>> Haha, okay Eli. It was just to be sure, because otherwise I have
>> no idea why setting the vscroll using the above code, does not
>> work here.
>>
>> I have tried with the Fedora system Emacs 28.3, and with my own
>> build of Emacs 29.1 (with PGTK, but I guess that is the default now
>> on Emacs 29). Also, I have tried on wayland and x-org. But the code
>> does not set the vscroll when starting from emacs -Q, while, strangely
>> it works when I load my configuration.
>>
>> Anyway, I guess I have to investigate some more then.
>>
>> Thanks a lot for checking!
>>
>>
>> On Sun, 5 Nov 2023 at 18:01, Eli Zaretskii <eliz@gnu.org> wrote:
>>
>>> > From: dalanicolai <dalanicolai@gmail.com>
>>> > Date: Sun, 5 Nov 2023 17:36:26 +0100
>>> > Cc: emacs-devel@gnu.org
>>> >
>>> > I just realized I forgot to be clear about my question.
>>> > The problem is that after evaluating the code, here,
>>> > after starting from emacs -Q, the vscroll value is still
>>> > zero.
>>> >
>>> > So I was wondering what is the value when doing
>>> >
>>> >  M-: (window-vscroll nil t)
>>> >
>>> > after evaluating the example code.
>>> >
>>> > So Eli, when you say it works, do you mean that
>>> > vscroll value is 300?
>>>
>>> Of course!  How else could I have claimed that "it works"?
>>>
>>