[Python-checkins] cpython (3.4): prevent unacceptable bases from becoming bases through multiple inheritance
benjamin.peterson
python-checkins at python.org
Tue Oct 6 22:42:56 EDT 2015
https://hg.python.org/cpython/rev/e670b37e7b14
changeset: 98573:e670b37e7b14
branch: 3.4
parent: 98568:03a569eb0e0e
user: Benjamin Peterson <benjamin at python.org>
date: Tue Oct 06 19:36:54 2015 -0700
summary:
prevent unacceptable bases from becoming bases through multiple inheritance (#24806)
files:
Lib/test/test_descr.py | 31 ++++++++++++++++++++++++++++++
Misc/NEWS | 3 ++
Objects/typeobject.c | 12 +++++-----
3 files changed, 40 insertions(+), 6 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
@@ -3735,6 +3735,37 @@
else:
assert 0, "best_base calculation found wanting"
+ def test_unsubclassable_types(self):
+ with self.assertRaises(TypeError):
+ class X(type(None)):
+ pass
+ with self.assertRaises(TypeError):
+ class X(object, type(None)):
+ pass
+ with self.assertRaises(TypeError):
+ class X(type(None), object):
+ pass
+ class O(object):
+ pass
+ with self.assertRaises(TypeError):
+ class X(O, type(None)):
+ pass
+ with self.assertRaises(TypeError):
+ class X(type(None), O):
+ pass
+
+ class X(object):
+ pass
+ with self.assertRaises(TypeError):
+ X.__bases__ = type(None),
+ with self.assertRaises(TypeError):
+ X.__bases__ = object, type(None)
+ with self.assertRaises(TypeError):
+ X.__bases__ = type(None), object
+ with self.assertRaises(TypeError):
+ X.__bases__ = O, type(None)
+ with self.assertRaises(TypeError):
+ X.__bases__ = type(None), O
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
Core and Builtins
-----------------
+- Issue #24806: Prevent builtin types that are not allowed to be subclassed from
+ being subclassed through multiple inheritance.
+
- Issue #24848: Fixed a number of bugs in UTF-7 decoding of misformed data.
- Issue #25280: Import trace messages emitted in verbose (-v) mode are no
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -1937,6 +1937,12 @@
if (PyType_Ready(base_i) < 0)
return NULL;
}
+ if (!PyType_HasFeature(base_i, Py_TPFLAGS_BASETYPE)) {
+ PyErr_Format(PyExc_TypeError,
+ "type '%.100s' is not an acceptable base type",
+ base_i->tp_name);
+ return NULL;
+ }
candidate = solid_base(base_i);
if (winner == NULL) {
winner = candidate;
@@ -2317,12 +2323,6 @@
if (base == NULL) {
goto error;
}
- if (!PyType_HasFeature(base, Py_TPFLAGS_BASETYPE)) {
- PyErr_Format(PyExc_TypeError,
- "type '%.100s' is not an acceptable base type",
- base->tp_name);
- goto error;
- }
dict = PyDict_Copy(orig_dict);
if (dict == NULL)
--
Repository URL: https://hg.python.org/cpython
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