[Python-checkins] cpython (2.7): Issue #5322: Fixed setting __new__ to a PyCFunction inside Python code.
serhiy.storchaka
python-checkins at python.org
Fri Dec 2 01:43:03 EST 2016
https://hg.python.org/cpython/rev/a37cc3d926ec
changeset: 105412:a37cc3d926ec
branch: 2.7
parent: 105410:0516f54491cb
user: Serhiy Storchaka <storchaka at gmail.com>
date: Fri Dec 02 08:42:43 2016 +0200
summary:
Issue #5322: Fixed setting __new__ to a PyCFunction inside Python code.
Original patch by Andreas Stührk.
files:
Lib/test/test_descr.py | 97 ++++++++++++++++++++++++++++++
Misc/NEWS | 3 +
Objects/typeobject.c | 28 ++++++++-
3 files changed, 127 insertions(+), 1 deletions(-)
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -3,6 +3,7 @@
import sys
import types
import unittest
+import warnings
import weakref
from copy import deepcopy
@@ -1550,6 +1551,84 @@
self.assertEqual(b.foo, 3)
self.assertEqual(b.__class__, D)
+ def test_bad_new(self):
+ self.assertRaises(TypeError, object.__new__)
+ self.assertRaises(TypeError, object.__new__, '')
+ self.assertRaises(TypeError, list.__new__, object)
+ self.assertRaises(TypeError, object.__new__, list)
+ class C(object):
+ __new__ = list.__new__
+ self.assertRaises(TypeError, C)
+ class C(list):
+ __new__ = object.__new__
+ self.assertRaises(TypeError, C)
+
+ def test_object_new(self):
+ class A(object):
+ pass
+ object.__new__(A)
+ self.assertRaises(TypeError, object.__new__, A, 5)
+ object.__init__(A())
+ self.assertRaises(TypeError, object.__init__, A(), 5)
+
+ class A(object):
+ def __init__(self, foo):
+ self.foo = foo
+ object.__new__(A)
+ object.__new__(A, 5)
+ object.__init__(A(3))
+ self.assertRaises(TypeError, object.__init__, A(3), 5)
+
+ class A(object):
+ def __new__(cls, foo):
+ return object.__new__(cls)
+ object.__new__(A)
+ self.assertRaises(TypeError, object.__new__, A, 5)
+ object.__init__(A(3))
+ object.__init__(A(3), 5)
+
+ class A(object):
+ def __new__(cls, foo):
+ return object.__new__(cls)
+ def __init__(self, foo):
+ self.foo = foo
+ object.__new__(A)
+ with warnings.catch_warnings(record=True) as w:
+ warnings.simplefilter('always', DeprecationWarning)
+ a = object.__new__(A, 5)
+ self.assertEqual(type(a), A)
+ self.assertEqual(len(w), 1)
+ object.__init__(A(3))
+ a = A(3)
+ with warnings.catch_warnings(record=True) as w:
+ warnings.simplefilter('always', DeprecationWarning)
+ object.__init__(a, 5)
+ self.assertEqual(a.foo, 3)
+ self.assertEqual(len(w), 1)
+
+ def test_restored_object_new(self):
+ class A(object):
+ def __new__(cls, *args, **kwargs):
+ raise AssertionError
+ self.assertRaises(AssertionError, A)
+ class B(A):
+ __new__ = object.__new__
+ def __init__(self, foo):
+ self.foo = foo
+ with warnings.catch_warnings():
+ warnings.simplefilter('error', DeprecationWarning)
+ b = B(3)
+ self.assertEqual(b.foo, 3)
+ self.assertEqual(b.__class__, B)
+ del B.__new__
+ self.assertRaises(AssertionError, B)
+ del A.__new__
+ with warnings.catch_warnings():
+ warnings.simplefilter('error', DeprecationWarning)
+ b = B(3)
+ self.assertEqual(b.foo, 3)
+ self.assertEqual(b.__class__, B)
+
def test_altmro(self):
# Testing mro() and overriding it...
class A(object):
@@ -3756,6 +3835,24 @@
self.assertEqual(isinstance(d, D), True)
self.assertEqual(d.foo, 1)
+ class C(object):
+ @staticmethod
+ def __new__(*args):
+ return args
+ self.assertEqual(C(1, 2), (C, 1, 2))
+ class D(C):
+ pass
+ self.assertEqual(D(1, 2), (D, 1, 2))
+
+ class C(object):
+ @classmethod
+ def __new__(*args):
+ return args
+ self.assertEqual(C(1, 2), (C, C, 1, 2))
+ class D(C):
+ pass
+ self.assertEqual(D(1, 2), (D, D, 1, 2))
+
def test_imul_bug(self):
# Testing for __imul__ problems...
# SF bug 544647
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
Core and Builtins
-----------------
+- Issue #5322: Fixed setting __new__ to a PyCFunction inside Python code.
+ Original patch by Andreas Stührk.
+
- Issue #28847: dubmdbm no longer writes the index file in when it is not
changed and supports reading read-only files.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -6304,7 +6304,33 @@
sanity checks and constructing a new argument
list. Cut all that nonsense short -- this speeds
up instance creation tremendously. */
- specific = (void *)type->tp_new;
+ PyObject *self = PyCFunction_GET_SELF(descr);
+ if (!self || !PyType_Check(self)) {
+ /* This should never happen because
+ tp_new_wrapper expects a type for self.
+ Use slot_tp_new which will call
+ tp_new_wrapper which will raise an
+ exception. */
+ specific = (void *)slot_tp_new;
+ }
+ else {
+ specific = ((PyTypeObject *)self)->tp_new;
+ /* Check that the user does not do anything
+ silly and unsafe like object.__new__(dict).
+ To do this, we check that the most derived
+ base that's not a heap type is this type. */
+ PyTypeObject *staticbase = type->tp_base;
+ while (staticbase &&
+ (staticbase->tp_flags & Py_TPFLAGS_HEAPTYPE))
+ staticbase = staticbase->tp_base;
+ if (staticbase &&
+ staticbase->tp_new != specific)
+ /* Seems to be unsafe, better use
+ slot_tp_new which will call
+ tp_new_wrapper which will raise an
+ exception if it is unsafe. */
+ specific = (void *)slot_tp_new;
+ }
/* XXX I'm not 100% sure that there isn't a hole
in this reasoning that requires additional
sanity checks. I'll buy the first person to
--
Repository URL: https://hg.python.org/cpython
More information about the Python-checkins
mailing list