[Exim] BUG: null pointer in refused relay message

There is a bug in the logging of refused relays. ie the log message looks
like:

2000-06-27 10:04:25 NULLrefused relay (host) to <solomongrundie@???>
from <dsfklj34534@???>

It appears that the first %s pointer is a NULL pointer (relay_msg2 is NULL).
While this doesn't really cause any harm on most systems, it's not
considered
correct either.

Here's the code snippet that prints this message:

smtp_in.c:
         log_write(1, LOG_MAIN|LOG_REJECT, "%srefused relay (%s) to <%s>
from "
            "<%s>%s%s%s",
            relay_msg2,
            relay_need_either? "sender & host_accept_relay" :
              host_allow_relay_anywhere? "sender" : "host",
            orig_receiver, sender_address,
            (sender_fullhost == NULL)? "" : " H=",
            (sender_fullhost == NULL)? "" : host_and_ident(),
            host_lookup_msg);
          break;     /* End of handling the RCPT TO command */

NOTE: I'm not subscribed to the list, so send any replies directly to me
pls.