If interning an instance of a string subclass, intern a real string object
with the same value instead. This ensures that a string (or string
subclass) object's ob_sinterned pointer is always a str (or NULL), and
that the dict of interned strings only has strs as keys.
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 3c03b9e..99a16ed 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -3553,10 +3553,26 @@
Py_DECREF(s);
return;
}
- t = (PyObject *)s;
- if (PyDict_SetItem(interned, t, t) == 0) {
- s->ob_sinterned = t;
- return;
+ /* Ensure that only true string objects appear in the intern dict,
+ and as the value of ob_sinterned. */
+ if (PyString_CheckExact(s)) {
+ t = (PyObject *)s;
+ if (PyDict_SetItem(interned, t, t) == 0) {
+ s->ob_sinterned = t;
+ return;
+ }
+ }
+ else {
+ t = PyString_FromStringAndSize(PyString_AS_STRING(s),
+ PyString_GET_SIZE(s));
+ if (t != NULL) {
+ if (PyDict_SetItem(interned, t, t) == 0) {
+ *p = s->ob_sinterned = t;
+ Py_DECREF(s);
+ return;
+ }
+ Py_DECREF(t);
+ }
}
PyErr_Clear();
}