bug#15945: chown: Does now allow setting user and users login group with numerical user ID

[Tormen]

Dear Gnu Team,

First off: Thanks for existing!! :)))

I think I just found a bug in chown... \o/ ;)

Details about my GNU/Linux system:
        Debian wheezy stable 7.2

        dpkg -S /bin/chown
        coreutils: /bin/chown

        dpkg -l|grep coreutils
        ii  coreutils      8.13-3.5    amd64   GNU core utilities

        uname -a
        Linux seven 3.10-0.bpo.3-amd64 #1 SMP Debian 3.10.11-1~bpo70+1
(2013-09-24) x86_64 GNU/Linux

        echo $SHELL
        /bin/zsh

I tried:
        chown 1001: /tmp/bla

Leading to:
        chown: invalid spec: `1001:'

But as 1001 == "me", it should have done a:
        chown me: /tmp/bla
(which works just fine).

Is this a bug or a feature ?

... it should be a bug except if there is a technical detail I am
missing here.

Best,

Tormen