bug#13334: 24.3.50; enhancement request: `C-0 M-n' reverses order of defaults

[Drew Adams]

> > The enhancement would be to let a zero prefix arg (e.g. `C-0') reverse
> > the list of available default values and then go to the first one
> > (previously the last one).  So you could cycle among the defaults in the
> > opposite order.
> 
> A slightly different approach would be to make it just go to the end of
> the history, without changing the order.  Then you could just use M-p to
> go backwards.  I guess that would not be hard to do (see
> `goto-history-element').

Agreed.  That is about as good.  (But again, it's not about the input
_history_.  It's about a set of possible default values.)

The only reason what I suggested might be considered slightly better
is that `C-p' is generally thought of as accessing the input history
(see the above confusion), not the defaults.

That's the case at the outset, but of course once you've used one of
`C-n' or `C-p' the other just reverses within the list (inputs or
defaults) that you started cycling, until you get back to the starting
point (origin, dividing the two lists).