bug#33331: 26; doc strings of `tabify' and `untabify'

[Drew Adams <drew.adams@oracle.com>]

> > AFAICT there's no need to add that optional
> > arg.  This would have been sufficient, and
> > it is what I would have expected:
> >
> > (defun untabify (start end)
> >   "..."
> >   (interactive
> >     (if current-prefix-arg
> >         (list (point-min) (point-max))
> >       (list (region-beginning) (region-end))))
> >   ...)
> >
> > Am I missing something?  Does adding that arg,
> > and using it only in `interactive', help?
> 
> If we are going to change those functions, I'd prefer instead to make
> a change that used the 3rd argument in non-interactive calls.

I was going to say, "Sure, go for it".  But what would
that mean in this case?  Non-interactively you already
supply the START and END.  What would be gained by
a Boolean argument that uses `point-min' and `point-max'
and ignores the values of START and END?

Doesn't make sense to me, but maybe I'm missing something.
Just what did you have in mind here?