Python3 decodes sys.argv for us, so only decode when necessary.

diff --git a/tornado/options.py b/tornado/options.py
index 35c695783c532df1d7305473784f05c4acfc3d90..17608af77dad553db34cd9577c8ab40283ce5c7c 100644 (file)
--- a/tornado/options.py
+++ b/tornado/options.py
@@ -55,6 +55,8 @@ import re
 import sys
 import time
 
+from tornado.escape import _unicode
+
 # For pretty log messages, if available
 try:
     import curses
@@ -295,7 +297,7 @@ class _Option(object):
         return value.lower() not in ("false", "0", "f")
 
     def _parse_string(self, value):
-        return value.decode("utf-8")
+        return _unicode(value)
 
 
 class Error(Exception):