GNU bug report logs - #70386
30.0.50; (recenter 0 t) does not put point on top of the window

Previous Next

Full log

Message #11 received at 70386 <at> debbugs.gnu.org (full text, mbox):

From: Ihor Radchenko <yantar92 <at> posteo.net>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 70386 <at> debbugs.gnu.org
Subject: Re: bug#70386: 30.0.50; (recenter 0 t) does not put point on top of
 the window
Date: Sun, 14 Apr 2024 19:36:04 +0000

Eli Zaretskii <eliz <at> gnu.org> writes:

>> 1. emacs -Q
>> 2. Insert the following into scratch buffer and put point at "recenter"
>
> Which "recenter": the one in the comment or the one in (recenter 0 t) ?

The "(recenter 0 t))" line.

>> (progn
>>   (require 'pixel-scroll)
>>   (pixel-scroll-precision-interpolate
>>    (* -1 (line-pixel-height)
>>       (max 0 (- (count-screen-lines (window-start) (point)) 2)))
>>    nil 1)
>>   ;; Call original recenter for final adjustment.
>>   (recenter 0 t))
>> 
>> 3. M-x eval-buffer
>> 4. Observe that scroll is not set to line 0, despite calling `recenter'
>
> I don't think I understand what you mean by "scroll is not set to line
> 0".  Please explain in more detail what you expected to happen (and
> why), and what did happen.

Expected is as per docstring:

    With a numeric prefix argument ARG, recenter putting point on screen line ARG
    relative to the selected window.

So, I expect that (recenter 0 t) will put the line at point on top of
the window and that (recenter 1 t) will put the line at point at the
second top line.

My expectation is met when I simply do emacs -Q M-: (recenter 0 t) or
emacs -Q M-: (recenter 1 t) on master.

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)

Sometimes, I also observe line at point moving beyond the screen.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.