asterisk: Fix incorrect seq_nr expectancies when precondition is used

Change-Id: Icc91c863912934d48252ad0882d5603c161cd8b6
---
M asterisk/IMS_ConnectionHandler.ttcn
1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/asterisk/IMS_ConnectionHandler.ttcn b/asterisk/IMS_ConnectionHandler.ttcn
index 8eb220d..8c4186e 100644
--- a/asterisk/IMS_ConnectionHandler.ttcn
+++ b/asterisk/IMS_ConnectionHandler.ttcn
@@ -1380,12 +1380,14 @@
 		var template (value) PDU_SIP_Response tx_resp;
 		var Via via;
 		var template (omit) charstring tx_sdp;
+		var integer invite_seq_nr;
 		var boolean peer_support_precondition := match(g_rx_sip_req.msgHeader.supported.optionsTags,
 							       superset("100rel", "precondition"));
 
 		/* Obtain params: */
 		f_ConnHdlr_parse_initial_SIP_INVITE(g_rx_sip_req);
 		via := g_rx_sip_req.msgHeader.via;
+		invite_seq_nr := g_pars.subscr.cp.sip_seq_nr;
 
 		f_ims_validate_register_P_Access_Network_info(g_rx_sip_req, exp_present := true);
 		f_ims_validate_invite_P_Preferred_Service(g_rx_sip_req, exp_present := true);
@@ -1464,7 +1466,7 @@
 						g_pars.subscr.cp.from_addr,
 						g_pars.subscr.cp.to_addr,
 						"PRACK", 200,
-						g_pars.subscr.cp.sip_seq_nr,
+						g_pars.subscr.cp.sip_seq_nr + 1,
 						"OK",
 						via,
 						body := omit);
@@ -1476,7 +1478,7 @@
 					g_pars.subscr.cp.from_addr,
 					g_pars.subscr.cp.to_addr,
 					f_tr_Via_response(via),
-					g_pars.subscr.cp.sip_seq_nr + 1,
+					g_pars.subscr.cp.sip_seq_nr + 2,
 					require := tr_Require(superset("precondition")),
 					body := ?);
 			as_SIP_expect_req(exp_req);
@@ -1505,13 +1507,14 @@
 						g_pars.subscr.cp.from_addr,
 						g_pars.subscr.cp.to_addr,
 						"UPDATE", 200,
-						g_pars.subscr.cp.sip_seq_nr,
+						g_pars.subscr.cp.sip_seq_nr + 2,
 						"OK",
 						via,
 						body := tx_sdp);
 			SIP.send(tx_resp);
 
-			g_pars.subscr.cp.sip_seq_nr := g_pars.subscr.cp.sip_seq_nr + 1;
+			/* Update to latest used seq_nr: */
+			g_pars.subscr.cp.sip_seq_nr := g_pars.subscr.cp.sip_seq_nr + 2;
 			/* 200 OK (INVITE) has no SDP if we use precondition: */
 			tx_sdp := omit;
 		} else {
@@ -1533,7 +1536,7 @@
 						g_pars.subscr.cp.from_addr,
 						g_pars.subscr.cp.to_addr,
 						via,
-						g_pars.subscr.cp.sip_seq_nr);
+						invite_seq_nr);
 		SIP.send(tx_resp);
 
 
@@ -1543,7 +1546,7 @@
 					   g_pars.subscr.cp.from_addr,
 					   g_pars.subscr.cp.to_addr,
 					   "INVITE", 200,
-					   g_pars.subscr.cp.sip_seq_nr,
+					   invite_seq_nr,
 					   "OK",
 					   via,
 					   body := tx_sdp);
@@ -1555,7 +1558,7 @@
 				      g_pars.subscr.cp.from_addr,
 				      g_pars.subscr.cp.to_addr,
 				      f_tr_Via_response(via),
-				      g_pars.subscr.cp.sip_seq_nr, *);
+				      invite_seq_nr, *);
 		as_SIP_expect_req(exp_req);
 	}
 	[fail_others] as_SIP_fail_resp(sip_expect_str);

