fixed memory leak on rejected connections

Fixes https://github.com/miguelgrinberg/Flask-SocketIO/issues/574

socketio/server.py

@@ -422,6 +422,8 @@ class Server(object):
             self.manager.disconnect(sid, namespace)
             self._send_packet(sid, packet.Packet(packet.ERROR,
                                                  namespace=namespace))
+            if sid in self.environ:  # pragma: no cover
+                del self.environ[sid]
             return False
         else:
             self._send_packet(sid, packet.Packet(packet.CONNECT,

tests/test_server.py

@@ -204,6 +204,7 @@ class TestServer(unittest.TestCase):
         handler.assert_called_once_with('123', 'environ')
         self.assertEqual(s.manager.connect.call_count, 1)
         self.assertEqual(s.manager.disconnect.call_count, 1)
+        self.assertEqual(s.environ, {})
         s.eio.send.assert_called_once_with('123', '4', binary=False)
 
     def test_handle_connect_namespace_rejected(self, eio):

tox.ini

@@ -22,7 +22,7 @@ basepython=python3.6
 deps=
     flake8
 commands=
-    flake8 --exclude=".*" --ignore=E402 socketio tests
+    flake8 --exclude=".*" --ignore=E402,E722 socketio tests
 
 [testenv:docs]
 basepython=python2.7