bug#43573: 26.1; set-process-buffer doesn't create a process marker

[Lars Ingebrigtsen <larsi@gnus.org>]

marmot-te <marmot-te@riseup.net> writes:

> I noticed that creating a buffer for a process with set-process-buffer
> does not create also a marker specific to that process that can be
> retrieved with process-mark afteward.
>
> While the documentation doesn’t imply it, and it not something
> obiously necessary, I still consider it as a bug for
> set-process-buffer because I see nowhere a function which can create
> such process marker.

Yes, pretty odd, but it's just a normal marker, I think, so if you want
it to point somewhere else, you can just use do

(set-marker (process-mark proc) (point-max) buffer)

or something?

However, while there is some potential for breakage here, I think it
makes sense to have set-process-buffer do this, so I've applied it to
Emacs 28.  If this breaks anything (and that is possible -- somebody
could be using `process-mark' as a weird way to keep track of what the
previous buffer was -- it should be reverted.

I think that's very unlikely, but I guess we'll find out.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no