bug#62194: 30.0.50; Two Eglot-over-Tramp tests are failing on master, passing on emacs-29

[Eli Zaretskii <eliz@gnu.org>]

> Cc: Michael Albinus <michael.albinus@gmx.de>, 62194@debbugs.gnu.org
> Date: Fri, 17 Mar 2023 17:45:43 +0100
> From: miha--- via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Though I do think that if a function that calls a-p-o with
> JUST-THIS-ONE=nil isn't internal, it should mention that it can run
> timers in its doc string.

I don't see why: timers can run in Emacs almost anywhere, so
mentioning that in doc strings of every function makes little sense.

> But here we are talking about 'expand-file-name' and other functions
> from tramp-sh-file-name-handler. For these, I disagree that we want them
> to accept output from other processes and call their filters.
> 'expand-file-name' and others are used often and, for most of the
> existence of Emacs, they did not call proc filters. I think it's
> dangerous to have them do it now.

Process filters can be also called at any time, because they basically
depend on when the output from a subprocess arrives.  Why would you
want that to stop while Emacs processes expand-file-name?

> 'expand-file-name' is synchronous, therefore tramp has to make it use
> accept-process-filter (tell me if there's another way). It can use it in
> roughly two ways: with JUST-THIS-ONE=t or JUST-THIS-ONE=nil. In the
> first case, we hit the eglot-over-ssh freeze problem and in the second
> case, we'll have 'expand-file-name' call timers and process filters,
> which I explained above why I don't like.

I think you should teach yourself to like that.