bug#24596: 25.1; `f10' behavior

[Eli Zaretskii]

> Date: Mon, 3 Oct 2016 09:33:47 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 24596@debbugs.gnu.org
> 
> > > 2. Why can you not exit `menu-bar-open' (with nil
> > > `tty-menu-open-use-tmm')?  Why is ESC the only way to cancel (at least
> > > on MS Windows)?  Why are not the canonical Emacs ways of canceling
> > > implemented here (`C-g' and `ESC ESC ESC')?
> > 
> > ESC ESC works for me on MS-Windows GUI frames.
> 
> For me, with emacs -Q, a single ESC cancels.  A second ESC acts as
> a prefix key for the next key sequence.

Sorry, I omitted a crucial detail: the number of ESC presses needed to
exit the menu depends on whether you already dropped a menu or not.
That is, if you press F10, then the down-arrow, to drop the File menu,
you need 2 ESC: the first will pop down the menu, the second will exit
the menu bar.  But if you just press F10, or only type right-arrow or
left-arrow after that, i.e. there's no menu dropped down, then just
one ESC is enough.

> > ESC ESC ESC and C-g
> > work for me on TTY frames.  C-g doesn't work on a GUI frame because
> > the menu is controlled by Windows, not by Emacs, and Windows doesn't
> > know about C-g.  IOW, this is a limitation we can do very little
> > about.
> 
> OK.  Then the fix is to fix the doc, which says something quite
> different from what the behavior really is.

I can only add a note there saying that with some toolkits the exact
keys to exit the menu might be different.  Any better ideas?

> The part about `C-g' and `ESC ESC ESC' is wrong, for Windows.  And if
> `C-g' is Emacs only and `menu-bar-open' passes the behavior off to a
> toolkit, then perhaps `C-g' is also incorrect for other toolkits/window
> managers?

I guess so, but I don't really know and have no way if verifying
that.  Help is welcome.