Ah yes... you are totally right of course.

So for the first question, (pdf-scroll.el is not required indeed),
do `M-x papyrus-demo`, maximize the demo window,
then scroll down a few pages, and split the buffer horizontally.
Now, the page in the other window does not get diplayed.

Then do `M-: (print "test")` and hide the echo-area by pressing
`esc`. Now the page does get displayed.

So my question is how can I achieve this without printing
something first.

On Sat, 16 Apr 2022 at 20:32, Eli Zaretskii <eliz@gnu.org> wrote:

> > From: dalanicolai <dalanicolai@gmail.com>
> > Date: Sat, 16 Apr 2022 20:17:11 +0200
> > Cc: Emacs Devel <emacs-devel@gnu.org>
> >
> > Well, for the second question, just do emacs -q,
> >  then load papyrus.el and do `M-x papyrus-demo`.
>
> And then do what? look where? for what issues?
>
> > For the first question pdf-tools is required to be installed,
> > I am not sure how to achieve that from emacs -q
> > (well besides building the server manually, after installing
> > pdf-tools using `list-packages` I guess).
>
> I don't understand.  It is your code that inserts the overlays which
> AFAIU give you the problems, right?  So I think it should be possible
> to construct a simple test case using some image file instead of what
> pdf-tools produce.
>
> > So maybe you could answer/comment on the second question.
>
> I don't think I understand the situation well enough to answer, sorry.
>