Re: esh-proc test failures

[Eli Zaretskii]

> Cc: larsi@gnus.org, emacs-devel@gnu.org
> From: Jim Porter <jporterbugs@gmail.com>
> Date: Tue, 23 Aug 2022 08:57:37 -0700
> 
> > I don't think I follow.  When the write fails, we get an error and
> > propagate it all the way up to the caller.
> 
> If we signal an error in a process filter, does Emacs inform the process 
> that wrote that data of the error? My tests showed that it didn't, but 
> maybe I was doing something wrong.

Why are you talking about the process filter?  Does that filter call
process-send-string to write to the next process in the pipe?  If so,
it should inform Emacs about any errors in writing.

> The goal here is just to tell a process that the thing it's writing to 
> is gone, and that it should give up.

That cannot happen, because Eshell is in-between.  Instead, it is
Emacs (Eshell) that should see the error, and deliver a signal to the
relevant process if needed.