Curious compare_tests bug

[Mike Stump]

> From: Nix <nix@esperi.demon.co.uk>
> Date: Sat, 28 Nov 1998 17:15:27 +0000 (GMT)

> While converting my test scripts to use compare_tests instead of
> diff &c, I noticed a curious presumed bug in compare_tests.

> Try compare_testing a .sum file with itself.

> Looking more closely, comm(1) appears to be spouting nonsense; This
> happens at least with comm(1) from the GNU textutils-1.22 and 1.22f.

It seems like a bug, works fine on solaris and FreeBSD.