Hello,
If the user never registered (or few hours passed from its unregister) the
subscription to REGINFO will return an empty body NOTIFY (no xml).
I don't see any flag in module to force a body for this case, as in the
presence module is force_dummy_presence who can force a body on a first
NOTIFY.
The RFC3680 says :
o Notifications triggered from a SUBSCRIBE contain full state
(the list of all contacts bound to the address-of-record).
It appears that in this case the response is not conform to RFC.
Regards,
Adrian