bug#35246: 26.2; Mouse wheel scrolling in GTK build sometimes scrolls the entire buffer

[Eli Zaretskii]

> Date: Mon, 15 Apr 2019 19:35:07 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 35246@debbugs.gnu.org
> 
> >   <help-echo> <down-mouse-5> <mouse-5> [mwheel-scroll]
> >   <double-down-mouse-5> <double-mouse-5> [mwheel-scroll]
> >   <triple-down-mouse-5> <triple-mouse-5> [mwheel-scroll]
> >   <triple-down-mouse-5> <triple-mouse-5> [mwheel-scroll]
> >   <triple-down-mouse-5> <triple-mouse-5> [mwheel-scroll]
> >   <triple-down-mouse-5> <triple-mouse-5> [mwheel-scroll]
> >   <triple-down-mouse-5> <triple-mouse-5> [mwheel-scroll]
> >   <down-mouse-4> <mouse-4> [mwheel-scroll]
> >   <double-down-mouse-4> <double-mouse-4> [mwheel-scroll]
> >   <help-echo> <down-mouse-5> <mouse-5> [mwheel-scroll]
> >   <down-mouse-5> <mouse-5> [mwheel-scroll]
> >   C-h l [view-lossage]
> 
> So somehow, Emacs receives a long series of mouse wheel-scrolling
> events, perhaps due to multiple down-mouse events.  And since we have
> mouse-wheel-progressive-speed, a series of such events produces
> scrolling far away.
> 
> The question is where did those events come from?  Is it possible that
> something is wrong with your mouse wheel or the driver?

What kind of mouse is this?  Is that by any chance a mouse pad of a
laptop?