bug#21315: 25.0.50; doc of `kill-ring-save', `copy-region-as-kill' - bad

[Drew Adams]

> say this:
>   The optional argument REGION non-nil means to ignore BEG and END and
>   copy the region instead.

Yes.

(But I think we usually phrase that as: "Non-nil optional argument
REGION means...".)

> Also, we should tell that this distinction is only relevant to
> invoking these functions from Lisp programs, not interactively.

Yes.

  From Lisp, non-nil optional argument REGION means...

> As for the argument, AFAICT it makes no difference in interactive
> usage.

Yes, it is always non-nil interactively: `prefix-numeric-value'
never returns nil.

> Does documenting the above clarify the issue?

Yes, I think so.  Thx.