Matthew's fixes to the unit tests

Extracted from https://github.com/matrix-org/synapse/pull/2820

tests/replication/slave/storage/_base.py

@@ -15,6 +15,8 @@
 from twisted.internet import defer, reactor
 from tests import unittest
 
+import tempfile
+
 from mock import Mock, NonCallableMock
 from tests.utils import setup_test_homeserver
 from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
@@ -41,7 +43,9 @@ class BaseSlavedStoreTestCase(unittest.TestCase):
         self.event_id = 0
 
         server_factory = ReplicationStreamProtocolFactory(self.hs)
-        listener = reactor.listenUNIX("\0xxx", server_factory)
+        # XXX: mktemp is unsafe and should never be used. but we're just a test.
+        path = tempfile.mktemp(prefix="base_slaved_store_test_case_socket")
+        listener = reactor.listenUNIX(path, server_factory)
         self.addCleanup(listener.stopListening)
         self.streamer = server_factory.streamer
 
@@ -49,7 +53,7 @@ class BaseSlavedStoreTestCase(unittest.TestCase):
         client_factory = ReplicationClientFactory(
             self.hs, "client_name", self.replication_handler
         )
-        client_connector = reactor.connectUNIX("\0xxx", client_factory)
+        client_connector = reactor.connectUNIX(path, client_factory)
         self.addCleanup(client_factory.stopTrying)
         self.addCleanup(client_connector.disconnect)