merge in patch from tim golden to fix contextmanager support for mp.Lock()
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index 105a743..a446ac3 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -546,6 +546,10 @@
         self.assertEqual(lock.release(), None)
         self.assertRaises((AssertionError, RuntimeError), lock.release)
 
+    def test_lock_context(self):
+        with self.Lock():
+            pass
+
 
 class _TestSemaphore(BaseTestCase):