Fix for
[ 784825 ] fix obscure crash in descriptor handling
Should be applied to release23-maint and in all likelyhood
release22-maint, too.
Certainly doesn't apply to release21-maint.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 5c0f73a..af255f1 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -2010,6 +2010,7 @@
return meta_get(meta_attribute, (PyObject *)type,
(PyObject *)metatype);
}
+ Py_INCREF(meta_attribute);
}
/* No data descriptor found on metatype. Look in tp_dict of this
@@ -2018,6 +2019,9 @@
if (attribute != NULL) {
/* Implement descriptor functionality, if any */
descrgetfunc local_get = attribute->ob_type->tp_descr_get;
+
+ Py_XDECREF(meta_attribute);
+
if (local_get != NULL) {
/* NULL 2nd argument indicates the descriptor was
* found on the target object itself (or a base) */
@@ -2031,13 +2035,16 @@
/* No attribute found in local __dict__ (or bases): use the
* descriptor from the metatype, if any */
- if (meta_get != NULL)
- return meta_get(meta_attribute, (PyObject *)type,
- (PyObject *)metatype);
+ if (meta_get != NULL) {
+ PyObject *res;
+ res = meta_get(meta_attribute, (PyObject *)type,
+ (PyObject *)metatype);
+ Py_DECREF(meta_attribute);
+ return res;
+ }
/* If an ordinary attribute was found on the metatype, return it now */
if (meta_attribute != NULL) {
- Py_INCREF(meta_attribute);
return meta_attribute;
}