Use `127.0.0.1` when binding test server socket.

diff --git a/tornado/testing.py b/tornado/testing.py
index 54d76fe40fecf451287e7c82e4069cb43f1604b0..119234d0471d6db8417bfec8f24d29ea6072cd68 100644 (file)
--- a/tornado/testing.py
+++ b/tornado/testing.py
@@ -97,8 +97,8 @@ def bind_unused_port(reuse_port=False):
 
     Returns a tuple (socket, port).
     """
-    [sock] = netutil.bind_sockets(None, 'localhost', family=socket.AF_INET,
-                                  reuse_port=reuse_port)
+    sock = netutil.bind_sockets(None, '127.0.0.1', family=socket.AF_INET,
+                                  reuse_port=reuse_port)[0]
     port = sock.getsockname()[1]
     return sock, port