bug#3736: 23.1.50; Please use null-device instead of /dev/null

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Date: Thu, 02 Jul 2009 14:22:38 +0200
> Cc: emacs-pretest-bug@gnu.org, 3736@emacsbugs.donarmstrong.com
> 
> Lennart Borgman <lennart.borgman@gmail.com> writes:
> 
> > There are nearly a hundred places in Emacs lisp sources where
> > /dev/null is used instead of null-device. Please convert those to use
> > null-device so that it gets system-independent. (I wonder what to do
> > with those in Tramp.)
> 
> On W32 systems, null-device is "NUL". Not useful for Tramp, it needs
> "/dev/null" on remote machines.

On remote machines, Tramp indeed shouldn't use a value that is correct
for the local OS.