Upstart script "restart" won't restart service

Binary package hint: xinetd

# stop xinetd
xinetd stop/waiting
# start xinetd
xinetd start/running, process 9378
# restart xinetd
xinetd start/running, process 9378

I must stop(8) then start(8) it to restart.

I investigate the upstart script at /etc/init/xinetd.conf. The pre-stop script is:

pre-stop script
  xinetd_pid=$(status | awk '/stop\/pre-stop/ { print $NF }')
  [ -n "${xinetd_pid}" ] || exit 0
  kill -QUIT "${xinetd_pid}"
end script

The first line gets nothing when invoking restart. I think that's because awk cannot match the pattern when invoing 'restart'. It matches when invoking 'stop'. I think using /var/run/xinetd.pid is safe. Changed it to this:

pre-stop script
  xinetd_pid=$(cat /var/run/xinetd.pid)
  [ -n "${xinetd_pid}" ] || exit 0
  kill -QUIT "${xinetd_pid}"
end script

This will stop the service but won't start it when invoking 'restart'. I do not know the internals of upstart. This may because the pre-stop exit with a non-zero status and 'restart' just killed it and cannot start it?

To fix the problem in the bug summary , I have to comment out the pre-stop script, and 'restart' works OK. I see bug 605007, the author need SIGQUIT, but in my way SIGQUIT is not explicitly sent. I do not know why SIGQUIT is needed.

IMHO, this script needs a fix. But I haven't figured out a good patch. Thank you guys.