Issue #23757: Only call the concrete list API for exact lists.
diff --git a/Lib/test/seq_tests.py b/Lib/test/seq_tests.py
index 9834af1..2416249 100644
--- a/Lib/test/seq_tests.py
+++ b/Lib/test/seq_tests.py
@@ -85,6 +85,14 @@
'Test multiple tiers of iterators'
return chain(map(lambda x:x, iterfunc(IterGen(Sequence(seqn)))))
+class LyingTuple(tuple):
+ def __iter__(self):
+ yield 1
+
+class LyingList(list):
+ def __iter__(self):
+ yield 1
+
class CommonTest(unittest.TestCase):
# The type to be tested
type2test = None
@@ -131,6 +139,10 @@
self.assertRaises(TypeError, self.type2test, IterNoNext(s))
self.assertRaises(ZeroDivisionError, self.type2test, IterGenExc(s))
+ # Issue #23757
+ self.assertEqual(self.type2test(LyingTuple((2,))), self.type2test((1,)))
+ self.assertEqual(self.type2test(LyingList([2])), self.type2test([1]))
+
def test_truth(self):
self.assertFalse(self.type2test())
self.assertTrue(self.type2test([42]))
diff --git a/Misc/NEWS b/Misc/NEWS
index e9b1461..2599b82 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -13,6 +13,9 @@
- Issue #20274: Remove ignored and erroneous "kwargs" parameters from three
METH_VARARGS methods on _sqlite.Connection.
+- Issue #23757: PySequence_Tuple() incorrectly called the concrete list API
+ when the data was a list subclass.
+
- Issue #24096: Make warnings.warn_explicit more robust against mutation of the
warnings.filters list.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 7e3121a..cabbaf5 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1636,7 +1636,7 @@
Py_INCREF(v);
return v;
}
- if (PyList_Check(v))
+ if (PyList_CheckExact(v))
return PyList_AsTuple(v);
/* Get iterator. */