Question about the email about "[PATCH 2/3] IPV6: unify 3 similar code path in ndisc_recv_ns()"

Dear David S. Miller :

Happy to write to you.
In the email  <20040206.181006.79694138.yoshfuji@linux-ipv6.org >
<http://oss.sgi.com/archives/netdev/2004-02/msg00111.html>>,
yoshfuji unified 3  similar code patch in ndisc_recv_ns(). I have a 
question
about the "flags sent with  
NA in reply to this NS" .  In the kernel 2.4.21,
it is as follows:
 ndisc_send_na(dev, neigh, saddr,
                  &msg->target,
                      idev->cnf.forwarding, 1, 0, inc);
in you patch it is as follows:
ndisc_send_na(dev, neigh, saddr, &msg->target,
                idev->cnf.forwarding,
                1, (ifp != NULL && inc), inc);
Can you tell me why you modified the flag O(override)?
Thanks a lot!

-- 
Regards
Ren Junyuan
 --------------------------------------------------
 Ren Junyuan
 Development Dept.I
 Nanjing Fujitsu Nanda Software Tech. Co., Ltd.(FNST)
 8/F., Civil Defense Building, No.189 Guangzhou Road,
 Nanjing, 210029, China 
 TEL: +86+25-86630566-851
 COINS: 79955-851
 FAX: +86+25-83317685
 MAIL: renjy@cn.fujitsu.com