Created attachment 535417 [details]
Patch to dracut version of dhclient-script to set fqdn

Description of problem:
When booting with nfsroot, dracut doesn't necessarily set the initial hostname correctly.

Version-Release number of selected component (if applicable):
dracut-network-013-18.fc16

How reproducible:
Always

Steps to Reproduce:
1.On a dhcp server configure option host-name = short; option domain-name example.domain; 
2. Boot client with systemd.unit=rescue.target
3. /bin/hostname
  
Actual results:
short

Expected results:
short.example.domain

Additional info:
According to dhcp-options(5), the name may or may not be qualified with the local domain. It goes on to say "it is preferable to use the domain-name option to specify the domain name".

So dhclient-script needs to be able to handle the cases: a) where host-name is fully qualified and domain name is also specified; b) where hostname is fully qualified and the domain is not separately specified; c) where host-name is "short" and domain-name is also specified; and d) do its best where host-name is short but domain-name is not specified.

The dhclient-script in initramfs does not handle case "c", apparently the preferred situation properly, setting hostname to "short".

Patch attached.