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

[Eli Zaretskii]

> Date: Sat, 10 Nov 2018 09:08:11 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 33331@debbugs.gnu.org
> 
> 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.