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

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Tue, 01 Oct 2019 17:36:49 +0200
> Cc: 5557@debbugs.gnu.org
> 
> Lennart Borgman <lennart.borgman@gmail.com> writes:
> 
> > This is rather inconvenient. I would expect the default binding for
> > double-wheel-down the left and right margin to be the same as in the
> > text part of the buffer. (Ie I would expect it to be bound to
> > mwheel-scroll.)
> >
> > Is there any reason not to bind it in the margins by default?
> 
> (I'm going through old bug reports that unfortunately didn't get any
> response at the time.)
> 
> I'm not quite sure what's being referred to here.  Emacs has a fringe
> area, and there a "margin" concept in the indentation functions, but is
> there also a "margin" concept in windows?

Yes, see set-window-margins.