Updates to the with-statement: - New semantics for __exit__() -- it must re-raise the exception if type is not None; the with-statement itself doesn't do this. (See the updated PEP for motivation.) - Added context managers to: - file - thread.LockType - threading.{Lock,RLock,Condition,Semaphore,BoundedSemaphore} - decimal.Context - Added contextlib.py, which defines @contextmanager, nested(), closing(). - Unit tests all around; bot no docs yet.

--- a/Python/errors.c	Tue Feb 28 21:41:30 2006 +0000
+++ b/Python/errors.c	Tue Feb 28 21:57:43 2006 +0000
@@ -24,6 +24,7 @@
 
 	if (traceback != NULL && !PyTraceBack_Check(traceback)) {
 		/* XXX Should never happen -- fatal error instead? */
+		/* Well, it could be None. */
 		Py_DECREF(traceback);
 		traceback = NULL;
 	}