bsc: Add TC_chan_rel_hard_rlsd_ms_dead

In this test case, the MSC performs a hard SCCP release of the
SCCP connection.  This makes the BSC send a RLL REL REQ on the lchan,
but we simulate a broken/lost MS which doesn't respond to that.

Current OsmoBSC master will fail this test, and that's exactly why we
need it.

Change-Id: I800168499c2ab30af72625aba6fc740bc16e5653
Related: OS#3333
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 9c0ec62..bab56d1 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -814,6 +814,21 @@
 	setverdict(pass);
 }
 
+/* Test behavior of channel release after hard RLSD from MSC and MS is not responding to RLL REL REQ */
+testcase TC_chan_rel_hard_rlsd_ms_dead() runs on test_CT {
+	var DchanTuple dt;
+
+	f_init(1);
+
+	dt := f_est_dchan('23'O, 23, '00010203040506'O);
+
+	/* release the SCCP connection */
+	BSSAP.send(ts_BSSAP_DISC_req(dt.sccp_conn_id, 0));
+
+	f_expect_chan_rel(0, dt.rsl_chan_nr, true, false);
+	setverdict(pass);
+}
+
 /* Test behavior of channel release after BSSMAP RESET from MSC */
 testcase TC_chan_rel_a_reset() runs on test_CT {
 	var DchanTuple dt;
@@ -2444,6 +2459,7 @@
 	execute( TC_chan_rel_conn_fail() );
 	execute( TC_chan_rel_hard_clear() );
 	execute( TC_chan_rel_hard_rlsd() );
+	execute( TC_chan_rel_hard_rlsd_ms_dead() );
 	execute( TC_chan_rel_a_reset() );
 
 	execute( TC_outbound_connect() );