bug#5557: <left-margin> <double-wheel-down> is undefined

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Sun, 16 Aug 2020 06:41:32 -0700
> Cc: rudalics@gmx.at, larsi@gnus.org, 5557@debbugs.gnu.org, 
>       lennart.borgman@gmail.com
> 
> On GTK, the horizontal scroll bar moves, but the window doesn't update.
> The behaviour is similar to the vertical case: the 'bar' portion moves,
> and when I then drag it with mouse-1, the window jumps to the position.
> 
> On Lucid, I see the same as for the vertical scroll bar: nothing happens.

What about a no-toolkit version?

> So it's starting to sound like we have at least two separate bugs to
> handle.

Sounds like that, yes.