testutil: make SignalMixin actually be a mixin (and not inherit from TestCase), use it from all tests that start notes and thus exec ifconfig

src/allmydata/test/test_iputil.py

@@ -1,12 +1,12 @@
 
-from allmydata.util import iputil
+from allmydata.util import iputil, testutil
 
 from twisted.trial import unittest
 import re
 
 DOTTED_QUAD_RE=re.compile("^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$")
 
-class ListAddresses(unittest.TestCase):
+class ListAddresses(testutil.SignalMixin, unittest.TestCase):
     def test_get_local_ip_for(self):
         addr = iputil.get_local_ip_for('127.0.0.1')
         self.failUnless(DOTTED_QUAD_RE.match(addr))

src/allmydata/test/test_queen.py

@@ -3,8 +3,9 @@ from twisted.trial import unittest
 from foolscap.eventual import flushEventualQueue
 
 from allmydata import queen
+from allmydata.util import testutil
 
-class Basic(unittest.TestCase):
+class Basic(testutil.SignalMixin, unittest.TestCase):
     def test_loadable(self):
         q = queen.Queen()
         d = q.startService()

src/allmydata/test/test_system.py

@@ -4,7 +4,7 @@ from twisted.trial import unittest
 from twisted.internet import defer, reactor
 from twisted.application import service
 from allmydata import client, queen, uri, download
-from allmydata.util import idlib, fileutil
+from allmydata.util import idlib, fileutil, testutil
 from foolscap.eventual import flushEventualQueue
 from twisted.python import log
 from twisted.python.failure import Failure
@@ -17,7 +17,7 @@ def flush_but_dont_ignore(res):
     d.addCallback(_done)
     return d
 
-class SystemTest(unittest.TestCase):
+class SystemTest(testutil.SignalMixin, unittest.TestCase):
 
     def setUp(self):
         self.sparent = service.MultiService()

src/allmydata/util/testutil.py

@@ -3,7 +3,7 @@ import os, signal, sys, time
 from twisted.internet import reactor
 from twisted.trial import unittest
 
-class SignalMixin(unittest.TestCase):
+class SignalMixin:
     # This class is necessary for any code which wants to use Processes
     # outside the usual reactor.run() environment. It is copied from
     # Twisted's twisted.test.test_process