RE: C-h k does not work with M-o

[Drew Adams]

> >> When I do C-h k M-o I see a line beginning with Set face:
> >
> > M-o is a prefix key. If you type another character, say `b',
> > then you should get help for the key sequence, say `M-o b'.
>
> Yes, but why does `C-h k M-o' display a command prompt?

Good point (and probably Robert's initial point, which I overlooked).

Apparently, Emacs thinks it should invoke `x-popup-menu' at that point, for
some reason.

I wonder if this thread is pertinent: "doc of prompt change with minor mode
for read-key-sequence" from 2006-09? Or at least I wonder if this might have
something to do with keyboard menus and "Hierarkey"?