bug#33050: 27.0.50; [macOS] Problem with process input with process-connection-type nil

[Eli Zaretskii <eliz@gnu.org>]

> From: Filipp Gunbin <fgunbin@fastmail.fm>
> Cc: Eli Zaretskii <eliz@gnu.org>,  33050@debbugs.gnu.org,  alan@idiocy.org
> Date: Sat, 27 Oct 2018 02:12:21 +0300
> 
> Thomas,

I'm not him, but since you asked...

> I don't really understand why pty mode is better here than pipe mode.
> Do we need job control, or escape sequences, or anything else specific
> to pty?

Yes, we want the buffering be as if ldapsearch was invoked from a
terminal.  Possibly also other features, but I don't know enough about
the program to tell.

Basically, if the program was written for interactive invocation
communicating through pty is always better.

> If we use pty, won't these features, on the contrary, get in
> the way somewhere?

If they get in the way, it's another bug, which needs to be analyzed
and solved.  It could be (although IMO improbable) that we decide to
go back to pipes, but then we will know why we did that, and we should
leave behind a comment with the explanation.

> Your suggestion to condionally fix this for Darwin on release looks
> good.

Right.