RE: Bikeshedding go! Why is <M-f4> unbound?

[Drew Adams]

> >>>     (global-set-key [M-f4] 'w32-syskey)

This is what I suggested - it's the Emacs way of defining keys. ;-)
But since no one had discussed it here in terms of implementation I guessed it
was not feasible as an approach.

If it is feasible and has no offsetting drawbacks (i.e., other things being
equal) then this is the best solution, IMO.  Nothing weird for Emacs users.  We
can predefine any keys we want this way to establish pass-through as their
default behavior.

> >> If we go that route why not just bind M-f4 to a function 
> >> that closes the current frame, as suggested at the beginning
> >> of this thread?
> > Because you want to support menu accelerators [Alt-<letter>] ?

I assume that `w32-syskey' here is a placeholder for pass-through to Windows.
Which means that Windows does what it wants with M-f4 (Alt-f4 might be better
here? dunno).

And this way it's clear that this is not an Emacs command for quitting Emacs or
closing the frame; Emacs just passes the key (not the associated action) to W32.
(Or so it appears to a user, at least.)

And the same binding (`w32-syskey') for a different key would indicate the same
thing: pass-through to Windows, again without indicating just what Windows does
with the key.

> I was not thinking along that line. The global binding at the 
> Lisp level is simplest solution, although maybe not the optimum: it 
> doesn't trigger the exit procedure when typed with the C-h prefix, but
> some may view that as an advantage. 

Yes, that is a good thing.  We should pass M-f4 through only if the key sequence
is M-f4, not if it is C-h k M-f4 or C-x M-f4 etc.

To pass through `C-x M-f4' also, that key sequence would also need to be bound
to `w32-syskey' - if not, Emacs would consider it unbound (and say so).  This is
normal for Emacs and Emacs users.