Issue #1066: implement PEP 3109, 2/3 of PEP 3134.
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index bc810b0..38ec577 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -125,7 +125,7 @@
             # Don't rely on sys.exc_info() still containing
             # the right information. Another exception may
             # have been raised and caught by an exit method
-            raise exc[0], exc[1], exc[2]
+            raise exc[0](exc[1]).with_traceback(exc[2])
 
 
 class closing(object):