Issue #13454: Fix a crash when deleting an iterator created by itertools.tee()
if all other iterators were very advanced before.
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index f6d0e23..ea82291 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -401,14 +401,31 @@
return 0;
}
+static void
+teedataobject_safe_decref(PyObject *obj)
+{
+ while (obj && Py_TYPE(obj) == &teedataobject_type &&
+ Py_REFCNT(obj) == 1) {
+ PyObject *nextlink = ((teedataobject *)obj)->nextlink;
+ ((teedataobject *)obj)->nextlink = NULL;
+ Py_DECREF(obj);
+ obj = nextlink;
+ }
+ Py_XDECREF(obj);
+}
+
static int
teedataobject_clear(teedataobject *tdo)
{
int i;
+ PyObject *tmp;
+
Py_CLEAR(tdo->it);
for (i=0 ; i<tdo->numread ; i++)
Py_CLEAR(tdo->values[i]);
- Py_CLEAR(tdo->nextlink);
+ tmp = tdo->nextlink;
+ tdo->nextlink = NULL;
+ teedataobject_safe_decref(tmp);
return 0;
}
@@ -475,6 +492,8 @@
if (to->index >= LINKCELLS) {
link = teedataobject_jumplink(to->dataobj);
+ if (link == NULL)
+ return NULL;
Py_DECREF(to->dataobj);
to->dataobj = (teedataobject *)link;
to->index = 0;