If a username is specified, make sure there's also a password

The password can be an empty string if `nopass` is specified.

1 files changed, 1 insertions, 1 deletions

diff --git a/redis/connection.py b/redis/connection.py
index 695a662..b90cafe 100755
--- a/redis/connection.py
+++ b/redis/connection.py
@@ -617,7 +617,7 @@ class Connection(object):
         # if username and/or password are set, authenticate
         if self.username or self.password:
             if self.username:
-                auth_args = (self.username, self.password)
+                auth_args = (self.username, self.password or '')
             else:
                 auth_args = (self.password,)
             # avoid checking health here -- PING will fail if we try