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

From: Eli Zaretskii <[email-masked]>
Date: Sat, 20 Oct 2018 13:09:48 +0300

> From: Filipp Gunbin <[email-masked]>
> Date: Mon, 15 Oct 2018 22:03:19 +0300
> 
> If I let-bind process-connection-type to t (use pty) in above code, then
> it works normally:
> 
> *Messages* :
> proc status: run
> found prompt
> proc status: run
> exited
> "exited"
> 
> Buffer "my-process-buf":
> enter something:
> Process my-process<2> finished
> 
> But if I let-bind process-connection-type to nil (so does ldap.el), then
> it hangs, and after a few seconds wait and C-g, *Messages* has only
> this: "proc status: run [6 times]", and buffer my-process-buf is empty.

The reason is almost certainly buffering: when the connection is via a
pipe, the subprocess writes in buffered mode, so it might take quite a
few characters of input before /usr/bin/read outputs something.  Try
using the -n or -N options, and see if that helps.

Why does ldap.el set process-connection-type to nil?