Leave alert_notification and outbind unanswered

test/session.test.ts

@@ -1792,6 +1792,26 @@ describe('a PDU the codec cannot read', () => {
 		assert.ok((await raceWithin(2000, failed)) instanceof Error, 'one sessionError per refused PDU');
 	});
 
+	test('answers neither alert_notification nor outbind, which have no response', async t => {
+		const { peer, session } = await bound(t);
+		let failures = 0;
+
+		session.on('sessionError', () => { failures++; });
+		peer.writeRaw(pduBytes({
+			cmdName: 'alert_notification',
+			params: { esme_addr: '46701234567', source_addr: '46709876543' },
+			seqNr: 3,
+		}));
+		peer.writeRaw(pduBytes({ cmdName: 'outbind', params: { password: 'pw', system_id: 'smsc' }, seqNr: 4 }));
+		peer.writeRaw(pduBytes({ cmdName: 'enquire_link', seqNr: 5 }));
+
+		const answered = await answerTo(peer);
+
+		assert.equal(answered.cmdName, 'enquire_link_resp');
+		assert.equal(answered.seqNr, 5);
+		assert.equal(failures, 0);
+	});
+
 	test('answers a deliver_sm with a truncated TLV stream with ESME_RINVTLVSTREAM', async t => {
 		const { peer, session } = await bound(t);
 		let reports = 0;