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

[Drew Adams]

> >> > Should Emacs not "actively shadow" `C-c' or `C-d' or ... when
> >> > launched from a shell, because those keys mean somthing to
> >> > the shell?
>
> That is not what I meant by "shadow".
> It is a similar situation but Emacs position is the master in this
> case while the operating system is the master in the case we are
> discussing.

Define "master".  You can certainly launch Emacs in background from a shell,
then kill it from the shell.  So much for Emacs being in control of the shell.
Why shouldn't Emacs pass C-c or C-d through to the shell, by your logic?

(Alt-F4 isn't OS, it's window mgr, though admittedly for Windows the two are
conflated.)

What is the hierachy you see and how does it relate to key bindings?  There are
several possible environments outside Emacs, all of which can have their own key
bindings.

* shell where you invoke Emacs (C-c,...)
* Window manager (Alt-F3,...)
* OS
* other outside apps with their "standard" keys (C-s, ...)
* ... (?)

Which ones should take precedence over Emacs when a key is unbound in Emacs
(pass-through)?  Which ones should take precedence even if a key _is_ bound in
Emacs?

I would say give Emacs users and libraries the choice whenever possible,
including the choice to do nothing or to raise an unbound error for a key that
some outside environment might normally handle.

If they choose to pass some things through to the outside or to mimic particular
outside (e.g. "standard") actions, so be it.