From 7b66ec0ae3b33aa28c1c0328dc0a62361b780124 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Leonel=20C=C3=A2mara?= <leonelcamara@gmail.com>
Date: Sun, 20 Nov 2016 19:51:51 +0000
Subject: [PATCH] Fixes #1506

---
 gluon/authapi.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gluon/authapi.py b/gluon/authapi.py
index 6ff67ab3..c4934b83 100644
--- a/gluon/authapi.py
+++ b/gluon/authapi.py
@@ -135,10 +135,10 @@ class AuthAPI(object):
         messages = self.messages = Messages(current.T)
         messages.update(self.default_messages)
         messages.lock_keys = True
-        if signature:
+        if signature is True:
             self.define_signature()
         else:
-            self.signature = None
+            self.signature = signature or None
 
     def __validate(self, value, requires):
         if not isinstance(requires, (list, tuple)):
@@ -251,7 +251,7 @@ class AuthAPI(object):
             settings.use_username = username
         if not self.signature:
             self.define_signature()
-        if signature:
+        if signature is True:
             signature_list = [self.signature]
         elif not signature:
             signature_list = []