bug#27442: Un-obsolete x-clipboard-yank, or provide analogous functional

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: monnier@iro.umontreal.ca,  Hi-Angel@yandex.ru,  27442@debbugs.gnu.org
> Date: Mon, 05 Jul 2021 22:11:22 +0200
> 
> (kill-new "foo")
> (gui-selection-value)
> => nil
> 
> Could we use a different way to identify this situation that's less
> fragile?

AFAIK, there's no reasonable way of doing a better check.

> Hm...  I don't really see any with our current low-level
> functions.  I think x-get-selection-internal could have returned more
> metadata -- the timestamp, for instance, which would have allowed us to
> see whether we ourselves really pushed the data to the clipboard.

Where would that time stamp come from?

> My analysis here may be wrong, but if this is the reason the code in
> that function is the way it is, I think the right fix here is the
> trivial patch I proposed, along with more comments in
> `gui-selection-value' that explains what the point of the
> duplicate-ignoring code is.

I admit I don't really understand what the patch does and how.  can
you elaborate on that?