diff options
| -rw-r--r-- | Lib/test/test_descr.py | 19 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Objects/typeobject.c | 9 |
3 files changed, 27 insertions, 4 deletions
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py index 964cc5c..4050524 100644 --- a/Lib/test/test_descr.py +++ b/Lib/test/test_descr.py @@ -1,7 +1,9 @@ import __builtin__ +import gc import sys import types import unittest +import weakref from copy import deepcopy from test import test_support @@ -1127,7 +1129,6 @@ order (MRO) for bases """ self.assertEqual(Counted.counter, 0) # Test lookup leaks [SF bug 572567] - import gc if hasattr(gc, 'get_objects'): class G(object): def __cmp__(self, other): @@ -4541,7 +4542,6 @@ order (MRO) for bases """ self.assertRaises(AttributeError, getattr, C(), "attr") self.assertEqual(descr.counter, 4) - import gc class EvilGetattribute(object): # This used to segfault def __getattr__(self, name): @@ -4590,6 +4590,21 @@ order (MRO) for bases """ foo = Foo() str(foo) + def test_cycle_through_dict(self): + # See bug #1469629 + class X(dict): + def __init__(self): + dict.__init__(self) + self.__dict__ = self + x = X() + x.attr = 42 + wr = weakref.ref(x) + del x + test_support.gc_collect() + self.assertIsNone(wr()) + for o in gc.get_objects(): + self.assertIsNot(type(o), X) + class DictProxyTests(unittest.TestCase): def setUp(self): class C(object): @@ -9,6 +9,9 @@ What's New in Python 2.7.3 release candidate 1? Core and Builtins ----------------- +- Issue #1469629: Allow cycles through an object's __dict__ slot to be + collected. (For example if ``x.__dict__ is x``). + - Issue #13521: dict.setdefault() now does only one lookup for the given key, making it "atomic" for many purposes. Patch by Filip Gruszczyński. diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 3db02ed..ce1d42b 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -876,8 +876,13 @@ subtype_clear(PyObject *self) assert(base); } - /* There's no need to clear the instance dict (if any); - the collector will call its tp_clear handler. */ + /* Clear the instance dict (if any), to break cycles involving only + __dict__ slots (as in the case 'self.__dict__ is self'). */ + if (type->tp_dictoffset != base->tp_dictoffset) { + PyObject **dictptr = _PyObject_GetDictPtr(self); + if (dictptr && *dictptr) + Py_CLEAR(*dictptr); + } if (baseclear) return baseclear(self); |