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

From: Bob Proulx <[email-masked]>
Date: Thu, 21 Nov 2013 09:47:23 -0700

Eric Blake wrote:
> OWNER':'
>      If a colon but no group name follows OWNER, that user is made the
>      owner of the files and the group of the files is changed to OWNER's
>      login group.

Long ago this was an existing behavior of GNU rm and discussion on the
list talked of removing it.  I defended it because I often used this
on various systems to set the default group of a user.  Because some
systems are configured with user-private-groups where the user is in a
private group while on other systems the user is in a shared "users"
group.  Using 'chown foo: file' was a nice way to set the group to
foo's default group without needing to figure out what that group was
ahead of time.  I don't know when it was introduced into GNU chown but
at the least I had been using it extensively.

> so it looks like we have a bug that if OWNER is numeric, we aren't
> looking up OWNER's login group.

Seems that way.

Bob