From e210a644aa982bd6502726a900c79ebdcbe8fdc2 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Tue, 28 Sep 2010 20:10:56 -0700
Subject: [PATCH] Make AsyncTestCase.stop() prefer _arg over **kwargs, even
 when the former is not truthy.

---
 tornado/testing.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tornado/testing.py b/tornado/testing.py
index a18d48fd7..d7d810742 100644
--- a/tornado/testing.py
+++ b/tornado/testing.py
@@ -139,7 +139,8 @@ class AsyncTestCase(unittest.TestCase):
         Keyword arguments or a single positional argument passed to stop() are
         saved and will be returned by wait().
         '''
-        self.__stop_args = _arg or kwargs
+        assert _arg is None or not kwargs
+        self.__stop_args = kwargs or _arg
         if self.__running:
             self.io_loop.stop()
             self.__running = False
-- 
2.47.3