Re: [PATCH 2/3] Don't print "process finished" into the stderr buffer.

[Eli Zaretskii <eliz@gnu.org>]

> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Fri, 19 Apr 2019 21:28:32 +0200
> Cc: Emacs developers <emacs-devel@gnu.org>, Philipp Stephani <phst@google.com>
> 
> > But I'm guessing that the current behavior was unexpected for some
> > reason, and that's why you looked in the documentation.  If the guess
> > is correct, could you describe why it was unexpected/unwanted?
> 
> It's unexpected that Emacs writes something. This is an instance of
> the general case that by default you expect nothing to happen instead
> of something, unless you request the "something". For example, after
> $ echo foo > bar
> would you expect that the file "bar" contains content other than
> "foo\n" because the shell decides to write additional text before
> closing redirections? This is the same thing.

But Emacs does that for ages, so in Emacs this is veteran behavior of
the default sentinel function.

> The documentation for make-process doesn't state that if :stderr is a
> buffer, make-process creates a pipe process with the default sentinel;

Actually, it does, albeit in the parent section:

     Alternatively, you could use the ‘:stderr’ parameter with a non-‘nil’
  value in a call to ‘make-process’ (*note make-process: Asynchronous
  Processes.) to make the destination of the error output separate from
  the standard output; in that case, Emacs will use pipes for
  communicating with the subprocess.