bug#71971: 31.0.50; Add user option server-window-alist

[Michael Albinus via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Jonas Bernoulli <jonas@bernoul.li> writes:

Hi,

> Thanks for the clarifications, I understand better now and agree its
> a worthwhile goal.  Unfortunately I have no idea how to do it, but I
> look forward to see what you and others come up with.  I can't think
> of anything myself, for now at least.

What I could imagine is, that emacsclient gets the option to send an
identification, a string, to the server. With this, on the server side,
a set of preferences (variables) could be set for a given
identification, which matches a regexp. Not only for server-window, but
any variable. This would look like

((REGEXP (VAR . VALUE) .. (VAR . VALUE))
 (REGEXP (VAR . VALUE) .. (VAR . VALUE))
 ...)

Any VAR, like server-window, would use its related VALUE, which has
precedence.

Packages, like magit, could prepare such preferences, and activate if
the corresponding emacsclient sends an identification which matches a
regexp. User could prepare their own preferences, and invoke emacsclient
with their private identification, like 'emacsclient --ident="my-identification"'.

On protocol level between emacsclient and server.el, we would need a new
command '-ident'. Or, if we must be backwards compatible, we could use
'eval' to set it, or we could use a special formatted '-comment'.

This doesn't say which variables we recommend to use for
preferences. Just a mean to communicate between emacsclient and
server.el.

> Cheers!

Best regards, Michael.