sgsn: introduce TC_attach_rau_a_a()

MS <-> SGSN: Successful Attach
MS  -> SGSN: Routing Area Update Request
MS <-  SGSN: Routing Area Update Accept
MS  -> SGSN: Routing Area Update Request
MS <-  SGSN: Routing Area Update Accept
MS  -> SGSN: Detach (PowerOff)

Change-Id: Id76b4792c07816bcbe5e965f23c2b526df0923c3
diff --git a/sgsn/SGSN_Tests.ttcn b/sgsn/SGSN_Tests.ttcn
index 336f38e..b55da88 100644
--- a/sgsn/SGSN_Tests.ttcn
+++ b/sgsn/SGSN_Tests.ttcn
@@ -1823,6 +1823,36 @@
 	}
 }
 
+private function f_TC_attach_rau_a_a(charstring id) runs on BSSGP_ConnHdlr {
+	var BssgpDecoded bd;
+
+	/* first perform regular attach */
+	f_TC_attach(id);
+
+	/* then send RAU */
+	f_routing_area_update(g_pars.ra);
+
+	/* do another RAU */
+	f_routing_area_update(g_pars.ra);
+
+	f_detach_mo(c_GMM_DTT_MO_GPRS, true, true);
+}
+
+testcase TC_attach_rau_a_a() runs on test_CT {
+	/* MS <-> SGSN: Successful Attach
+	 * MS  -> SGSN: Routing Area Update Request
+	 * MS <-  SGSN: Routing Area Update Accept
+	 * MS  -> SGSN: Routing Area Update Request
+	 * MS <-  SGSN: Routing Area Update Accept
+	 * MS  -> SGSN: Detach (PowerOff)
+	 */
+	var BSSGP_ConnHdlr vc_conn;
+	f_init();
+	f_sleep(1.0);
+	vc_conn := f_start_handler(refers(f_TC_attach_rau_a_a), testcasename(), g_gb, 37);
+	vc_conn.done;
+}
+
 control {
 	execute( TC_attach() );
 	execute( TC_attach_mnc3() );
@@ -1848,6 +1878,7 @@
 	execute( TC_hlr_location_cancel_request_unknown_subscriber_update(), 10.0 );
 	execute( TC_rau_unknown() );
 	execute( TC_attach_rau() );
+	execute( TC_attach_rau_a_a() );
 	execute( TC_detach_unknown_nopoweroff() );
 	execute( TC_detach_unknown_poweroff() );
 	execute( TC_detach_nopoweroff() );