bug#56239: 28.1; Cannot send signals by name to inferior process by calling signal-process interactively

[Eli Zaretskii]

> Cc: 56239@debbugs.gnu.org, Daniel Martín <mardani29@yahoo.es>
> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Mon, 27 Jun 2022 12:41:29 +0200
> 
> Michael Albinus <michael.albinus@gmx.de> writes:
> 
> > Unfortunately, it's not such simple. signal-process can also deliver a
> > signal to a process running on a remote host. The signal names on that
> > host might differ from the signal names on the local host, collected by
> > Fsignal_names.
> >
> > How do we want to handle this? I don't see a simple solution, because
> > the file name handler machinery is not in use here.
> 
> I think users will just have to use numbers in those cases (which is
> still possible).  I.e., the symbol names are a convenience where it
> works, but if not, then users can't use those.

I agree, but there's a larger problem here: signal numbers that
correspond to given names are also system-dependent.  That is, SIGINT
could be 2 on one system and 295 on another.  So if you type

  M-x signal-process RET INT RET

you could send to the process a signal number that will be interpreted
on the remote host as some completely different signal.

So I think we should at least document that symbolic names should be
used for remote processes only very carefully, if at all.