Subject: Re: bug#30349: 27.0.50; Cuonfusing documentation about pipe processes

From: Noam Postavsky <[email-masked]>
Date: Tue, 6 Feb 2018 19:05:54 -0500

On Tue, Feb 6, 2018 at 1:55 PM, Eli Zaretskii <[email-masked]> wrote:

>> > Could it be that the phrase originally meant shell-style redirection?
>>
>> Perhaps, but none of those functions support that, as far as I know.
>
> Did you look at Git history of how that text was introduced?  Maybe
> that will tell us something.  Or maybe the discussions/bug report
> around the time this text was written/modified will give a hint.

Huh. I had assumed it was new in make-process, but actually the phrase
seems to have come from start-process where it was present since the
beginning [1: d0d6b7c].
I see it's also in start-process-shell-command, where it could refer
to shell redirection, so maybe it was copied from there?
Although, IMO, even in start-process-shell-command it doesn't really
make much sense: if you use shell redirection you haven't stopped the
output from going into BUFFER, there just happens not to be any
output.

[1: d0d6b7c]: 1992-03-14 20:40:04 +0000
  Initial revision
  https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=d0d6b7c506eb0f93e80db38d6c2affe0a2b49b4c

> (Sorry I'm not doing this research myself, but I'm terribly busy these
> days, and won't have time for it for another couple of days.)

No problem.

>>     :buffer BUFFER -- BUFFER is the buffer (or buffer-name) to associate
>>     with the process.  Process output goes at end of that buffer, unless
>>     you specify a filter function to handle the output.  [...]
>
> Yes.  And then the sentence about the default filter function.

Hmm, I know I have a personal tendency for terseness, but that really
seems redundant to me:

    :buffer BUFFER -- BUFFER is the buffer (or buffer-name) to associate
    with the process.  Process output goes at end of that buffer, unless
    you specify a filter function to handle the output.  The default
    filter function writes process output at the end of that buffer. [...]