diff -r 72db185a8ab1 Lib/test/test_collections.py --- a/Lib/test/test_collections.py Wed Oct 14 12:02:39 2015 +0200 +++ b/Lib/test/test_collections.py Wed Oct 14 18:12:52 2015 +0300 @@ -1995,6 +1995,20 @@ class OrderedDictTests: with self.assertRaises(KeyError): od.move_to_end('x', 0) + def test_move_to_end_issue25406(self): + OrderedDict = self.module.OrderedDict + od = OrderedDict.fromkeys('abc') + od.move_to_end('c', last=False) + self.assertEqual(list(od), list('cab')) + od.move_to_end('a', last=False) + self.assertEqual(list(od), list('acb')) + + od = OrderedDict.fromkeys('abc') + od.move_to_end('a') + self.assertEqual(list(od), list('bca')) + od.move_to_end('c') + self.assertEqual(list(od), list('bac')) + def test_sizeof(self): OrderedDict = self.module.OrderedDict # Wimpy test: Just verify the reported size is larger than a regular dict diff -r 72db185a8ab1 Objects/odictobject.c --- a/Objects/odictobject.c Wed Oct 14 12:02:39 2015 +0200 +++ b/Objects/odictobject.c Wed Oct 14 18:12:52 2015 +0300 @@ -618,37 +618,26 @@ static _ODictNode * static void _odict_add_head(PyODictObject *od, _ODictNode *node) { - if (_odict_FIRST(od) == NULL) { - _odictnode_PREV(node) = NULL; - _odictnode_NEXT(node) = NULL; - _odict_FIRST(od) = node; + _odictnode_PREV(node) = NULL; + _odictnode_NEXT(node) = _odict_FIRST(od); + if (_odict_FIRST(od) == NULL) _odict_LAST(od) = node; - } - else { - _odictnode_PREV(node) = NULL; - _odictnode_NEXT(node) = _odict_FIRST(od); - _odict_FIRST(od) = node; + else _odictnode_PREV(_odict_FIRST(od)) = node; - } + _odict_FIRST(od) = node; od->od_state++; } static void _odict_add_tail(PyODictObject *od, _ODictNode *node) { - if (_odict_LAST(od) == NULL) { - _odictnode_PREV(node) = NULL; - _odictnode_NEXT(node) = NULL; + _odictnode_PREV(node) = _odict_LAST(od); + _odictnode_NEXT(node) = NULL; + if (_odict_LAST(od) == NULL) _odict_FIRST(od) = node; - _odict_LAST(od) = node; - } - else { - _odictnode_PREV(node) = _odict_LAST(od); - _odictnode_NEXT(node) = NULL; + else _odictnode_NEXT(_odict_LAST(od)) = node; - _odict_LAST(od) = node; - } - + _odict_LAST(od) = node; od->od_state++; }