bug#26599: patch for mwheel.el

[Eli Zaretskii]

> Date: Sun, 23 Apr 2017 15:13:00 +0900 (JST)
> Cc: 26599@debbugs.gnu.org, tkk@misasa.okayama-u.ac.jp
> From: Tak Kunihiro <tkk@misasa.okayama-u.ac.jp>
> 
> >> Is it possible to add a line that runs hook on `mwheel.el' to let me
> >> do so without advice-add?
> > 
> > Wouldn't it be better to have a user option which would turn off
> > auto-hscroll-mode without running any hooks?
> 
> Yes.  A concern is how to turn auto-hscroll-mode t back.

maybe I misunderstand something: what I had in mind is turn off
auto-hscroll-mode as part of the mwheel commands, then turn it back on
when the mwheel command did its job.

> User decides when to set auto-scroll-mode t again by an event besides
> wheel-up, -down, -left, or -down.

No, I meant to have it off as long as the mwheel command runs, and
restore it right back immediately afterwards.