cast curl debug messages to str

since they come in as bytes on Python 3

diff --git a/tornado/curl_httpclient.py b/tornado/curl_httpclient.py
index 77c9537cbbe38f12820edd0768d304012b5ba27e..9a0402b5f6da404e22120dbaf0c7d5bde5bc0b81 100644 (file)
--- a/tornado/curl_httpclient.py
+++ b/tornado/curl_httpclient.py
@@ -499,6 +499,7 @@ class CurlAsyncHTTPClient(AsyncHTTPClient):
 
     def _curl_debug(self, debug_type, debug_msg):
         debug_types = ('I', '<', '>', '<', '>')
+        debug_msg = native_str(debug_msg)
         if debug_type == 0:
             curl_log.debug('%s', debug_msg.strip())
         elif debug_type in (1, 2):