magic-removal: Improved QOperator.get_sql() to NOT output parenthesis in where clause if there is no where clause

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2257 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -451,7 +451,9 @@ class QOperator:
             joins.update(joins2)
             where.extend(where2)
             params.extend(params2)
+        if where:
             return tables, joins, ['(%s)' % self.operator.join(where)], params
+        return tables, joins, [], params
 
 class QAnd(QOperator):
     "Encapsulates a combined query that uses 'AND'."