fix the ignoring of __cmp__ method on metaclasses #7491
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 0b21f57..87d30eb 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1222,6 +1222,15 @@
# This used to crash
self.assertRaises(TypeError, MyABC.a.__set__, u, 3)
+ def test_metaclass_cmp(self):
+ # See bug 7491.
+ class M(type):
+ def __cmp__(self, other):
+ return -1
+ class X(object):
+ __metaclass__ = M
+ self.assertTrue(X < M)
+
def test_dynamics(self):
# Testing class attribute propagation...
class D(object):
diff --git a/Misc/NEWS b/Misc/NEWS
index c90b69f..76f2377 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@
Core and Builtins
-----------------
+- Issue #7491: Metaclass's __cmp__ method was ignored.
+
- Issue #7466: segmentation fault when the garbage collector is called
in the middle of populating a tuple. Patch by Florent Xicluna.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 8c49096..8ef23d5 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -628,7 +628,11 @@
int c;
/* Make sure both arguments are types. */
- if (!PyType_Check(v) || !PyType_Check(w)) {
+ if (!PyType_Check(v) || !PyType_Check(w) ||
+ /* If there is a __cmp__ method defined, let it be called instead
+ of our dumb function designed merely to warn. See bug
+ #7491. */
+ Py_TYPE(v)->tp_compare || Py_TYPE(w)->tp_compare) {
result = Py_NotImplemented;
goto out;
}