Inconsistent default behavior?

[Hui Gary Zhang]

I seems to observe some inconsistency when sh-utils hand the default,
meaning without an argument for 'id', 'logname', 'groups'.

After I("huiz") su and become root, here is the outputs from those
commands

>bash-2.05a# id
>uid=0(root) gid=0(root) groups=0(root)
>bash-2.05a# groups
>root
>bash-2.05a# logname
>huiz

It's clear that 'id' and 'groups' understand that I am currently root.
But 'logname' reports who I am before su.  It doesn't seem to be obvious
to me why it should behave this way.

---Gary