Hello,

Someone (who prefers to be anonymous) sent me a patch to add the ability
to su to set the primary group on the command line, like newgrp does.
So we can have:

	su user
	su user:group
	su :group (equivalent to newgrp)

This is useful for executing commands from cron or whatever, and
controlling the group explicitly.  The code is already committed,
but disabled. I am thinking of enabling it, but I want to make sure
first that people don't object to it, and that it does not introduce
any security issues.

Comments?

christos