fix rfc 3311

Author: souradeep.bera

libsofia-sip-ua/nua/nua_session.c

@@ -3333,7 +3333,7 @@ static int nua_update_client_request(nua_client_request_t *cr,
 	   (cri && cri->cr_offer_sent && !cri->cr_answer_recv) ||
 	   (cri && cri->cr_offer_recv && !cri->cr_answer_sent)) {
    if (session_get_description(sip, NULL, NULL))
-     return nua_client_return(cr, 500, "Overlapping Offer/Answer", msg);
+     return nua_client_return(cr, 500, "Overlapping Offer/Answer 1", msg);
   }
   else if (!sip->sip_payload) {
     soa_init_offer_answer(nh->nh_soa);
@@ -3552,7 +3552,7 @@ int nua_update_server_init(nua_server_request_t *sr)
 	  break;
 
     if (nh->nh_soa && overlap) {
-		return nua_server_retry_after(sr, 500, "Overlapping Offer/Answer", 1, 9);
+		return nua_server_retry_after(sr, 500, "Overlapping Offer/Answer 2", 1, 9);
 	}
 
     if (nh->nh_soa &&