Fix transform headers bug

diff --git a/tornado/web.py b/tornado/web.py
index 86aa1f3405f11db6d567cdce5a471dd69408d61f..27fc8f94c794cac3c1ce4262c32670865fcabfde 100644 (file)
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -694,11 +694,12 @@ class RequestHandler(object):
             self._handle_request_exception(e)
 
     def _generate_headers(self):
+        headers = self._headers
         for transform in self._transforms:
-            headers = transform.transform_headers(self._headers)
+            headers = transform.transform_headers(headers)
         lines = [self.request.version + " " + str(self._status_code) + " " +
                  httplib.responses[self._status_code]]
-        lines.extend(["%s: %s" % (n, v) for n, v in self._headers.iteritems()])
+        lines.extend(["%s: %s" % (n, v) for n, v in headers.iteritems()])
         for cookie_dict in getattr(self, "_new_cookies", []):
             for cookie in cookie_dict.values():
                 lines.append("Set-Cookie: " + cookie.OutputString(None))