From a751c0e03a501f78ece7fc7599da9b3d5ff7af1a Mon Sep 17 00:00:00 2001
From: Michele Comitini <mcm@glisco.it>
Date: Thu, 24 Jan 2013 01:42:58 +0100
Subject: [PATCH] Compliance with rfc6749.  Added backward compatibility with
 Facebook custom implementation.  Simpler and faster flow.

---
 gluon/contrib/login_methods/oauth20_account.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gluon/contrib/login_methods/oauth20_account.py b/gluon/contrib/login_methods/oauth20_account.py
index f9b04ecf..abc8f418 100644
--- a/gluon/contrib/login_methods/oauth20_account.py
+++ b/gluon/contrib/login_methods/oauth20_account.py
@@ -167,7 +167,8 @@ server for requests.  It can be used for the optional"scope" parameters for Face
                 tmp = e.read()
                 raise Exception(tmp)
             finally:
-                del current.session.code  # throw it away
+                if current.session.code:
+                    del current.session.code  # throw it away
 
             if open_url:
                 try: