bug#24596: 25.1; `f10' behavior

[Drew Adams <drew.adams@oracle.com>]

> > > 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.

Got it.  Can the doc please say this?  I tried ESC ESC ESC with just
f10, and I thought that the behavior was not as described.

> > > 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?

That will help.  Thx.  Is the ESC behavior as you described above?  If
so then it would help to mention it, I think.

I guess you are also saying that C-g is supported for at least some
toolkits.

> > 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.

Hopefully someone with another platform/toolkit will help here.