bug#27530: patch to cut and copy secondary

[Eli Zaretskii]

> Date: Thu, 07 Sep 2017 21:35:20 +0900 (JST)
> Cc: 27530@debbugs.gnu.org, tkk@misasa.okayama-u.ac.jp
> From: Tak Kunihiro <tkk@misasa.okayama-u.ac.jp>
> 
> > If we want a function that will put region around secondary selection,
> > why not write such a function, and let users who want to code commands
> > that use this functionality do that?  IOW, why do we have to come up
> > with a command to do something which we aren't sure is a frequent use
> > case?
> 
> How about having those in subr.el?
> 
>  -- Function: overlay-exchange-region overlay
>  -- Function: overlay-exists-p overlay
>  -- Function: overlay-to-region overlay
>  -- Function: overlay-from-region overlay

Hard to answer that, without some details.  Can you tell in a few
words what each function is supposed to do?