Test receiving FIN packet while disconnected.

tests/test_connection.py

@@ -148,3 +148,19 @@ def test_syn_repeat(self):
 
         self.assertEqual(json.loads(m_calls[-1][0][0]), expected_fin_packet)
         self.assertEqual(m_calls[-1][0][1], address)
+
+    def test_receive_fin_packet_while_disconnected(self):
+        fin_rudp_packet = packet.RUDPPacket(
+            0,
+            self.own_addr,
+            self.addr1,
+            fin=True
+        )
+
+        self.proto_mock.reset_mock()
+        self.handler_mock.reset_mock()
+
+        self.con.receive_packet(fin_rudp_packet)
+        connection.REACTOR.runUntilCurrent()
+
+        self.handler_mock.handle_shutdown.assert_not_called()

txrudp/connection.py

@@ -128,10 +128,11 @@ def receive_packet(self, rudp_packet):
                 that the packet had already been validated against
                 packet.RUDP_PACKET_JSON_SCHEMA.
         """
-        if rudp_packet.fin:
-            self.shutdown()
-        elif self.connected:
-            self._process_casual_packet(rudp_packet)
+        if self.connected:
+            if rudp_packet.fin:
+                self.shutdown()
+            else:
+                self._process_casual_packet(rudp_packet)
         elif rudp_packet.syn:
             self._process_syn_packet(rudp_packet)