bug#71646: 29.3; pixel-scroll-precision-mode overrides paging behaviour even when pixel-scroll-precision-interpolate-page is off

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

> Ping!
>
>> Cc: 71646@debbugs.gnu.org
>> Date: Sat, 22 Jun 2024 11:57:43 +0300
>> From: Eli Zaretskii <eliz@gnu.org>
>> 
>> > From: Mike Woolley <mike@bulsara.com>
>> > Date: Wed, 19 Jun 2024 11:44:52 +0100
>> > 
>> > Playing with `pixel-scroll-precision-mode’ I noticed a small issue:
>> > 
>> > Setting `pixel-scroll-precision-interpolate-page’ is supposed to turn off the paging animation (which it does)
>> > however even when it’s off, <prior> and <next> invoke `cua-scroll-up’ & `cua-scroll-down’ rather than allowing
>> > another keymap to handle it.
>> > 
>> > Unfortunately this means any other mapping for these keys you might have has now been silently overridden
>> > (even after you’ve said you don’t want the new behaviour).
>> > 
>> > (defun pixel-scroll-interpolate-up ()
>> >   "Interpolate a scroll upwards by one page."
>> >   (interactive)
>> >   (if pixel-scroll-precision-interpolate-page
>> >       (pixel-scroll-precision-interpolate (window-text-height nil t) nil 1)
>> >     (cua-scroll-down)))
>> > 
>> > I think it would be better if `pixel-scroll-precision-mode’ did nothing if `pixel-scroll-precision-interpolate-page’ is
>> > off and allowed another keycap to handle <prior> & <next>.
>> > 
>> > I also noticed that it only maps <prior> & <next> and not C-v / M-v, so in other words behaviour could be
>> > different depending on exactly which Page Up & Down key sequence you invoke.
>> 
>> Po Lu, any comments or suggestions?

Mike, is there any reason in particular you cannot remove the bindings
of `prior' and `next' from `pixel-scroll-precision-mode-map'?