diff --git a/Lib/test/test_subclassinit.py b/Lib/test/test_subclassinit.py index 0267e417177..6a12fb1ee0f 100644 --- a/Lib/test/test_subclassinit.py +++ b/Lib/test/test_subclassinit.py @@ -133,20 +133,32 @@ class Test(unittest.TestCase): def test_set_name_error(self): class Descriptor: def __set_name__(self, owner, name): - raise RuntimeError + 1/0 - with self.assertRaises(RuntimeError): - class A: - d = Descriptor() + with self.assertRaises(RuntimeError) as cm: + class NotGoingToWork: + attr = Descriptor() + + exc = cm.exception + self.assertRegex(str(exc), r'\bNotGoingToWork\b') + self.assertRegex(str(exc), r'\battr\b') + self.assertRegex(str(exc), r'\bDescriptor\b') + self.assertIsInstance(exc.__cause__, ZeroDivisionError) def test_set_name_wrong(self): class Descriptor: def __set_name__(self): pass - with self.assertRaises(TypeError): - class A: - d = Descriptor() + with self.assertRaises(RuntimeError) as cm: + class NotGoingToWork: + attr = Descriptor() + + exc = cm.exception + self.assertRegex(str(exc), r'\bNotGoingToWork\b') + self.assertRegex(str(exc), r'\battr\b') + self.assertRegex(str(exc), r'\bDescriptor\b') + self.assertIsInstance(exc.__cause__, TypeError) def test_set_name_lookup(self): resolved = [] diff --git a/Misc/NEWS b/Misc/NEWS index 237c9288e6c..4410edadf9a 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,9 @@ What's New in Python 3.6.0 beta 3 Core and Builtins ----------------- +- Issue #28214: Improved exception reporting for problematic __set_name__ + attributes. + - Issue #23782: Fixed possible memory leak in _PyTraceback_Add() and exception loss in PyTraceBack_Here(). diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 1021a75308c..bfbeb40d2c7 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -7022,8 +7022,13 @@ set_names(PyTypeObject *type) if (set_name != NULL) { tmp = PyObject_CallFunctionObjArgs(set_name, type, key, NULL); Py_DECREF(set_name); - if (tmp == NULL) + if (tmp == NULL) { + _PyErr_FormatFromCause(PyExc_RuntimeError, + "Error calling __set_name__ on '%.100s' instance %R " + "in '%.100s'", + value->ob_type->tp_name, key, type->tp_name); return -1; + } else Py_DECREF(tmp); }