[MERGE] ORM: fix result of queries using auto_join.

It is possible to have multiple results linked to a same 'left-side' query, such as having a task with several unread messages. In this case, the query using the joins gives back as many lines as unread messages, because of the joins in the query.
To avoid using distinct or 'where exist' constructs, the results of the query is filtered while keeping the original order.

bzr revid: tde@openerp.com-20121221131120-boll9klrxxna6zeq

openerp/osv/orm.py

@@ -4857,7 +4857,15 @@ class BaseModel(object):
             return res[0][0]
         cr.execute('SELECT "%s".id FROM ' % self._table + from_clause + where_str + order_by + limit_str + offset_str, where_clause_params)
         res = cr.fetchall()
-        return [x[0] for x in res]
+
+        # TDE note: with auto_join, we could have several lines about the same result
+        # i.e. a lead with several unread messages; we uniquify the result using
+        # a fast way to do it while preserving order (http://www.peterbe.com/plog/uniqifiers-benchmark)
+        def _uniquify_list(seq):
+            seen = set()
+            return [x for x in seq if x not in seen and not seen.add(x)]
+
+        return _uniquify_list([x[0] for x in res])
 
     # returns the different values ever entered for one field
     # this is used, for example, in the client when the user hits enter on