sudo -i, prompt missing hostname

System with root user password set in installer:
[chris@f23m ~]$ sudo -i
[root@f23m ~]# rpm -q sudo
sudo-1.8.15-1.fc23.x86_64
[root@f23m ~]# echo $PS1
[\u@\h \W]\$


System with root user not set in installer
[chris@f23a ~]$ sudo -i
[sudo] password for chris:
-bash-4.3# rpm -q sudo
sudo-1.8.15-1.fc23.x86_64
-bash-4.3# echo $PS1
\s-\v\$

Of course the problem is without creating root user, there is no
/root/.bashrc or /root/.bash_profile.

Is it sane to always create those files, even if root user password
isn't set? That way sudo -i still results in a descriptive prompt? If
it's sane, I'll file an RFE.

Thanks,


-- 
Chris Murphy