ns2: add test case to call force unconfigured after SNS Size received

The old ns dummy crashed when calling force unconfigured while sending
SNS SIZE.

Change-Id: I16d89391c0d665485cf453c260531023de6096fb
diff --git a/ns/NS_Tests.ttcn b/ns/NS_Tests.ttcn
index 9fbd5ab..a0b9216 100644
--- a/ns/NS_Tests.ttcn
+++ b/ns/NS_Tests.ttcn
@@ -626,6 +626,21 @@
 	f_clean_ns_codec();
 }
 
+/* Ensure the ns2 code doesn't crash when calling force unconfigured while sending SNS SIZE */
+testcase TC_sns_rx_size_force_unconf() runs on RAW_Test_CT {
+	g_handle_rx_alive := true;
+	f_init_vty();
+	f_init_ns_codec(mp_nsconfig);
+	f_init_ns_codec(mp_nsconfig, 1);
+	f_ns_exp(tr_SNS_SIZE(mp_nsconfig.nsei, rst_flag := true, max_nsvcs := ?,
+				num_v4 := ?, num_v6 := omit));
+	f_vty_transceive(NSVTY, "nsvc nsei " & int2str(mp_nsconfig.nsei) & " force-unconfigured");
+	f_ns_exp(tr_SNS_SIZE(mp_nsconfig.nsei, rst_flag := true, max_nsvcs := ?,
+				num_v4 := ?, num_v6 := omit));
+	setverdict(pass);
+	f_clean_ns_codec();
+}
+
 /* Test if SNS fails when all signalling NSVCs failes
  * 3GPP TS 48.016 § 7.4b.1.1
  * 1. do success SNS configuration
@@ -712,6 +727,7 @@
 		execute( TC_sns_bss_del() );
 		execute( TC_sns_bss_add_change_del() );
 		execute( TC_sns_bss_all_signalling_nsvcs_failed() );
+		execute( TC_sns_rx_size_force_unconf() );
 	}
 }