merge 70783 to py3k
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index ed8c626..29f823d 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -548,6 +548,10 @@
         self.assertEqual(lock.release(), None)
         self.assertRaises((AssertionError, RuntimeError), lock.release)
 
+    def test_lock_context(self):
+        with self.Lock():
+            pass
+
 
 class _TestSemaphore(BaseTestCase):