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

[Drew Adams]

> > Any Lisp code today can decide to capture the unbound error using
> > `condition-case', as mentioned earlier.  You can determine 
> > at the Lisp level what happens when an unbound error is raised.
> 
> But this can't be done when entering a command (in Emacs command
> loop). Or am I missing something?

Irrelevant.  I said in Lisp.  You answer "Not in bananas".

> And in the cases where you are not entering a key sequences in the
> command loop you can test if the given key sequence is unbound.

I already said this, but here goes again:

Testing whether a key is unbound is not the same thing as testing whether an
unbound error is raised.  The latter does tell you whether a key is unbound, but
it also tells you that a key was invoked and an error was raised because it is
not bound.