primitivus: fixes contact group update

frontends/src/quick_frontend/quick_contact_list.py

@@ -54,7 +54,14 @@ class QuickContactList(object):
         self.specials.clear()
 
     def replace(self, jid, groups=None, attributes=None):
-        """add a contact to the list if doesn't exist, else update it"""
+        """Add a contact to the list if doesn't exist, else update it.
+
+        @param jid (JID)
+        @param groups (list): list of groups or None to ignore the groups membership.
+        @param attributes (dict)
+
+        XXX: None value for 'groups' has a different meaning than [None] which is for the default group.
+        """
         if attributes and 'name' in attributes:
             self.setCache(jid, 'name', attributes['name'])