rlm_detail and empty packets

[Brian Candler]

I was trying to find out why reply_log wasn't logging successful 
authentications [freeradius 3.0.x]

It turns out there is hard-coded logic in rlm_detail.c to ignore packets 
which don't contain any AV pairs:

         if (!packet->vps) {
                 RWDEBUG("Skipping empty packet");
                 return 0;
         }

This is unfortunate because I was hoping to see e.g.

Thu Feb 22 13:53:29 2018
         Packet-Type = Access-Accept
         Timestamp = 1519307609

I can force it to work by adding a spurious Reply-Message attribute, but 
that seems silly.  Setting "log_packet_header" doesn't make any 
difference, because the empty packet check is made very early on.

Was there a reason for suppressing these logs? Would it be worth having 
a config switch for this?

Regards,

Brian.