only accept AttributeError as indicating no __prepare__ attribute on a metaclass, allowing lookup errors to propogate
diff --git a/Lib/test/test_metaclass.py b/Lib/test/test_metaclass.py
index 000bcf5..219ab99 100644
--- a/Lib/test/test_metaclass.py
+++ b/Lib/test/test_metaclass.py
@@ -230,6 +230,20 @@
42
>>>
+Test failures in looking up the __prepare__ method work.
+ >>> class ObscureException(Exception):
+ ... pass
+ >>> class FailDescr:
+ ... def __get__(self, instance, owner):
+ ... raise ObscureException
+ >>> class Meta(type):
+ ... __prepare__ = FailDescr()
+ >>> class X(metaclass=Meta):
+ ... pass
+ Traceback (most recent call last):
+ [...]
+ test.test_metaclass.ObscureException
+
"""
__test__ = {'doctests' : doctests}
diff --git a/Misc/NEWS b/Misc/NEWS
index ee43e63..a04e068 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@
Core and Builtins
-----------------
+- Handle errors from looking up __prepare__ correctly.
+
- Issue #5939: Add additional runtime checking to ensure a valid capsule
in Modules/_ctypes/callproc.c.
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 7fe164f..5c7138e 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -108,8 +108,16 @@
}
prep = PyObject_GetAttrString(meta, "__prepare__");
if (prep == NULL) {
- PyErr_Clear();
- ns = PyDict_New();
+ if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
+ PyErr_Clear();
+ ns = PyDict_New();
+ }
+ else {
+ Py_DECREF(meta);
+ Py_XDECREF(mkw);
+ Py_DECREF(bases);
+ return NULL;
+ }
}
else {
PyObject *pargs = PyTuple_Pack(2, name, bases);