bug#15873: 24.3.50; Make F10 toggle the tmm menu

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Wed, 14 Aug 2019 19:42:25 -0700
> Cc: 15873@debbugs.gnu.org
> 
> >>From "emacs -Q":
> > 1. Mx menu-bar-mode
> > 2. F10
> > 3. F10
> >
> > The first F10 opens up the tmm menu, but the second one tries to do
> > the same, and fails, obviously.
> >
> > IMO, than behavior doesn't make sense, Instead, please make F10 close
> > the tmm menu if it is already open.  (that would make the behavior
> > also consistent with that of drop-down TTY menus).
> >
> > TIA.
> >
> > In GNU Emacs 24.3.50.1 (i686-pc-mingw32)
> >  of 2013-11-06 on LEG570
> 
> (I'm going through old bug reports that have unfortunately gotten no
> responses yet.)
> 
> I've tried reproducing this bug in Emacs 27 both with -nw and without
> (but under Linux), and I'm not able to.  Are you still seeing this
> problem in a modern Emacs?

I still see it in Emacs 27 both on GNU/Linux (in a -nw session) and on
MS-Windows.