diff --git a/Objects/classobject.c b/Objects/classobject.c index bc2234528b8..80aabbf6c28 100644 --- a/Objects/classobject.c +++ b/Objects/classobject.c @@ -2414,19 +2414,29 @@ instancemethod_call(PyObject *func, PyObject *arg, PyObject *kw) } static PyObject * -instancemethod_descr_get(PyObject *meth, PyObject *obj, PyObject *class) +instancemethod_descr_get(PyObject *meth, PyObject *obj, PyObject *cls) { /* Don't rebind an already bound method, or an unbound method - of a class that's not a base class of class */ - if (PyMethod_GET_SELF(meth) != NULL || - (PyMethod_GET_CLASS(meth) != NULL && - !PyObject_IsSubclass(class, PyMethod_GET_CLASS(meth)))) { + of a class that's not a base class of cls. */ + + if (PyMethod_GET_SELF(meth) != NULL) { + /* Already bound */ Py_INCREF(meth); return meth; } - if (obj == Py_None) - obj = NULL; - return PyMethod_New(PyMethod_GET_FUNCTION(meth), obj, class); + /* No, it is an unbound method */ + if (PyMethod_GET_CLASS(meth) != NULL && cls != NULL) { + /* Do subclass test. If it fails, return meth unchanged. */ + int ok = PyObject_IsSubclass(cls, PyMethod_GET_CLASS(meth)); + if (ok < 0) + return NULL; + if (!ok) { + Py_INCREF(meth); + return meth; + } + } + /* Bind it to obj */ + return PyMethod_New(PyMethod_GET_FUNCTION(meth), obj, cls); } PyTypeObject PyMethod_Type = {