sort's -u is Failing to Check all -k fields for Uniqueness.

[Ralph Corderoy]

Hi,

This seems wrong.

    $ echo 1/3,1/2,1/1,2/1 | tr , \\012 | sort -nu -t / -k 1,2
    1/3
    2/1
    $

-u should only filter out lines that compare equal on *all* key fields.
I've opened an Ubuntu bug at
https://launchpad.net/distros/ubuntu/+source/coreutils/+bug/56891 which
has more detail and examples.  I was hoping someone here could either
confirm it's a bug or point out my misunderstanding.

Cheers,


Ralph.