From: sobolevn <mail@sobolevn.me>
Date: Tue, 15 Apr 2025 11:13:51 +0000 (+0300)
Subject: gh-132176: Fix crash on `type()` when `tuple` subclass passed as `bases` (#132212)
X-Git-Tag: v3.14.0b1~472
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b6c552f9e614bab4acf21584baed997f57e74114;p=thirdparty%2FPython%2Fcpython.git

gh-132176: Fix crash on `type()` when `tuple` subclass passed as `bases` (#132212)

Co-authored-by: Victor Stinner <vstinner@python.org>
---

diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index d80d317aab1d..87081a6db4ea 100644
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -1838,6 +1838,15 @@ class ClassCreationTests(unittest.TestCase):
         with self.assertRaises(RuntimeWarning):
             type("SouthPonies", (Model,), {})
 
+    def test_tuple_subclass_as_bases(self):
+        # gh-132176: it used to crash on using
+        # tuple subclass for as base classes.
+        class TupleSubclass(tuple): pass
+
+        typ = type("typ", TupleSubclass((int, object)), {})
+        self.assertEqual(typ.__bases__, (int, object))
+        self.assertEqual(type(typ.__bases__), TupleSubclass)
+
 
 class SimpleNamespaceTests(unittest.TestCase):
 
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index b817ae6e6843..3a7fad4681b2 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -497,10 +497,11 @@ _PyType_GetBases(PyTypeObject *self)
 static inline void
 set_tp_bases(PyTypeObject *self, PyObject *bases, int initial)
 {
-    assert(PyTuple_CheckExact(bases));
+    assert(PyTuple_Check(bases));
     if (self->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
         // XXX tp_bases can probably be statically allocated for each
         // static builtin type.
+        assert(PyTuple_CheckExact(bases));
         assert(initial);
         assert(self->tp_bases == NULL);
         if (PyTuple_GET_SIZE(bases) == 0) {