bug#61227: 29.0.60; Customize UI for customization of keys

[Drew Adams]

> > > > If defcustom type `key-sequence' is being used,
> > >
> > > No, it's 'key', not 'key-sequence'.
> >
> > OK, thx.  I guess that's something new in Emacs 29.
> > I don't see it in 28.2 or before.  Hopefully the
> > doc makes clear the difference between `key' and
> > `key-sequence', whatever it is.
> >
> > Does `key' type let you specify a command name, for
> > a remapping key binding?  That was my suggestion.
> 
> Here's what the ELisp manual says about it:
>   ‘key’
>        The value is a valid key according to ‘key-valid-p’, and suitable
>        for use with, for example ‘keymap-set’.

Thx.

Both `key-valid-p' and `keymap-set' are presumably
only in Emacs 29.  Guess I'll have to wait for
Emacs 29 to find out what it means.

(A wild guess is that it doesn't respond to my
suggestion to let users customize key bindings
using command remapping.)