Revert behavior of dangling period(hanging schema qualifier)

Related to #261.
Reverting to previous behavior until a way to handle behavior/grouping
of invalid sql is agreed upon.

sqlparse/engine/grouping.py

@@ -99,10 +99,10 @@ def valid_prev(token):
     def valid_next(token):
         sqlcls = sql.SquareBrackets, sql.Function
         ttypes = T.Name, T.String.Symbol, T.Wildcard
-        return imt(token, i=sqlcls, t=ttypes)
+        return token is None or imt(token, i=sqlcls, t=ttypes)
 
     def post(tlist, pidx, tidx, nidx):
-        return pidx, nidx
+        return (pidx, nidx) if nidx is not None else (pidx, tidx)
 
     _group(tlist, sql.Identifier, match, valid_prev, valid_next, post)
 

tests/test_grouping.py

@@ -89,9 +89,9 @@ def test_identifier_invalid(self):
         p = sqlparse.parse('a.')[0]
         self.assert_(isinstance(p.tokens[0], sql.Identifier))
         self.assertEqual(p.tokens[0].has_alias(), False)
-        self.assertEqual(p.tokens[0].get_name(), 'a')
-        self.assertEqual(p.tokens[0].get_real_name(), 'a')
-        self.assertEqual(p.tokens[0].get_parent_name(), None)
+        self.assertEqual(p.tokens[0].get_name(), None)
+        self.assertEqual(p.tokens[0].get_real_name(), None)
+        self.assertEqual(p.tokens[0].get_parent_name(), 'a')
 
     def test_identifier_as_invalid(self):  # issue8
         p = sqlparse.parse('foo as select *')[0]