If the data is None, use an empty string in the hash instead.

- Legacy-Id: 275

ietf/contrib/wizard.py

@@ -134,10 +134,18 @@ class Wizard( object ):
         Subclasses may want to take into account request-specific information
         such as the IP address.
         """
-        data = [(bf.name, bf.data) for bf in form] + [settings.SECRET_KEY]
+	data = []
+	for bf in form:
+	    if bf.data is None:
+		d = ''
+	    else:
+	    	d = bf.data
+	    data.append((bf.name, d))
+	data.append(settings.SECRET_KEY)
         # Use HIGHEST_PROTOCOL because it's the most efficient. It requires
         # Python 2.3, but Django requires 2.3 anyway, so that's OK.
         #pickled = pickle.dumps(data, protocol=pickle.HIGHEST_PROTOCOL)
+	print "hashing %s" % data
         pickled = str(data)     #XXX
         return md5.new(pickled).hexdigest()