Check the Py_TPFLAGS_HAVE_RICHCOMPARE flag before using the

tp_richcompare field!  (Hopefully this will make Python 2.1 binary
compatible with certain Zope extensions. :-)

diff --git a/Objects/object.c b/Objects/object.c
index 6dbd14c38744c848366fb1e8c1404ef7c674c944..40c939a20d788424c65c0deae8afee81d7721d31 100644 (file)
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -371,6 +371,10 @@ PyObject_Unicode(PyObject *v)
 }
 
 
+/* Macro to get the tp_richcompare field of a type if defined */
+#define RICHCOMPARE(t) (PyType_HasFeature((t), Py_TPFLAGS_HAVE_RICHCOMPARE) \
+                         ? (t)->tp_richcompare : NULL)
+
 /* Map rich comparison operators to their swapped version, e.g. LT --> GT */
 static int swapped_op[] = {Py_GT, Py_GE, Py_EQ, Py_NE, Py_LT, Py_LE};
 
@@ -387,13 +391,13 @@ try_rich_compare(PyObject *v, PyObject *w, int op)
        richcmpfunc f;
        PyObject *res;
 
-       if ((f = v->ob_type->tp_richcompare) != NULL) {
+       if ((f = RICHCOMPARE(v->ob_type)) != NULL) {
                res = (*f)(v, w, op);
                if (res != Py_NotImplemented)
                        return res;
                Py_DECREF(res);
        }
-       if ((f = w->ob_type->tp_richcompare) != NULL) {
+       if ((f = RICHCOMPARE(w->ob_type)) != NULL) {
                return (*f)(w, v, swapped_op[op]);
        }
        res = Py_NotImplemented;
@@ -414,8 +418,7 @@ try_rich_compare_bool(PyObject *v, PyObject *w, int op)
        PyObject *res;
        int ok;
 
-       if (v->ob_type->tp_richcompare == NULL &&
-           w->ob_type->tp_richcompare == NULL)
+       if (RICHCOMPARE(v->ob_type) == NULL && RICHCOMPARE(w->ob_type) == NULL)
                return 2; /* Shortcut, avoid INCREF+DECREF */
        res = try_rich_compare(v, w, op);
        if (res == NULL)
@@ -447,8 +450,7 @@ try_rich_to_3way_compare(PyObject *v, PyObject *w)
        };
        int i;
 
-       if (v->ob_type->tp_richcompare == NULL &&
-           w->ob_type->tp_richcompare == NULL)
+       if (RICHCOMPARE(v->ob_type) == NULL && RICHCOMPARE(w->ob_type) == NULL)
                return 2; /* Shortcut */
 
        for (i = 0; i < 3; i++) {
@@ -954,7 +956,7 @@ PyObject_Hash(PyObject *v)
        PyTypeObject *tp = v->ob_type;
        if (tp->tp_hash != NULL)
                return (*tp->tp_hash)(v);
-       if (tp->tp_compare == NULL && tp->tp_richcompare == NULL) {
+       if (tp->tp_compare == NULL && RICHCOMPARE(tp) == NULL) {
                return _Py_HashPointer(v); /* Use address as hash value */
        }
        /* If there's a cmp but no hash defined, the object can't be hashed */