problem with ns snapshot

[Huang Hai <thumahh@chpcc.edu.cn>]

Hi,

I have downloaded ns snapshot dated Mar. 8th, but when I use SACK to do some
simulation, it print out

        Agent::sendmsg(int, const AppData*, const char*) not implemented

and aborted. IMO, sendmsg should do nothing for there is actually no user's
data to send. I have modified sendmsg, it does nothing now. After that,
my script can run smoothly with ns. I hope the problem can be fixed in the
next snapshot. I also found that Agent::sendto will print out the same
error message and abort, and the error message it prints out says also

        Agent::sendmsg(int, const AppData*, const char*) not implemented

At least the error message should be "Agnet::sendto(.....) not implemented"

Huang