diff options
Diffstat (limited to 'Objects/abstract.c')
| -rw-r--r-- | Objects/abstract.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/Objects/abstract.c b/Objects/abstract.c index f0e01f7691..de5652f3e6 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -2379,9 +2379,16 @@ abstract_issubclass(PyObject *derived, PyObject *cls) int r = 0; while (1) { - if (derived == cls) + if (derived == cls) { + Py_XDECREF(bases); /* See below comment */ return 1; - bases = abstract_get_bases(derived); + } + /* Use XSETREF to drop bases reference *after* finishing with + derived; bases might be the only reference to it. + XSETREF is used instead of SETREF, because bases is NULL on the + first iteration of the loop. + */ + Py_XSETREF(bases, abstract_get_bases(derived)); if (bases == NULL) { if (PyErr_Occurred()) return -1; @@ -2395,7 +2402,6 @@ abstract_issubclass(PyObject *derived, PyObject *cls) /* Avoid recursivity in the single inheritance case */ if (n == 1) { derived = PyTuple_GET_ITEM(bases, 0); - Py_DECREF(bases); continue; } for (i = 0; i < n; i++) { |