[BUG?] dhclient sends packets with source IP address that has been deleted

[Yuri]

I am observing what dhclient sends to the server. Source IP of the 
packet it sends is the previous DHCP lease. This address doesn't exist 
any more, because I manually deleted it with 'ifconfig em0 remove <IP>' 
command. Yet, when I rerun dhclient, it takes this address from 
/var/db/dhclient.leases.em0 and sends the UDP packet with this 
non-existent IP as source address in IP header.

This looks very weird to me, though I am not sure what the practical 
implications of this might be. My guess is that it is able to do this 
because it injects packets with bpf.
Should this thing be fixed, or this is harmless?

Some other host might have this IP address by the time dhclient runs, 
and this might cause confusion somewhere.

10.1 STABLE

Yuri