Re: Is there any particular reason `scroll-other-window' is written in C and not in ELisp?

[Marcin Borkowski <mbork@mbork.pl>]

On 2015-12-29, at 17:02, Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Marcin Borkowski <mbork@mbork.pl>
>> Date: Tue, 29 Dec 2015 10:32:00 +0100
>
> Because it needs to determine the new window-start which is a
> window-full above or below the current one, without assuming that all
> the lines have the same height in pixels.  How do you do that in Lisp?
> (The current implementation simulates display.)

Interesting, though I know too little about Emacs internals to fully
understand your answer.  I thought it just does something like

(save-excursion
  (other-buffer)
  (scroll-up))

Why my (probably naïve) implementation won't work?

>> The reason I'm asking is that C-M-v (and C-M-S-v, for that matter) do
>> the wrong thing if the other window shows a pdf file using pdf-tools.
>> If those commands were written in Elisp, I could not only advise them
>> (which I can, and probably will), but also propose a patch or
>> something.
>
> Sounds like a bug that should be reported.  Not sure if it's in core
> Emacs or not, but please do report it with all the necessary details
> to whatever the guilty parties are.

Not Emacs core, you're right.  I'll file a bug report.

> Thanks.

Thanks

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University