Enhance issubclass() and PyObject_IsSubclass() so that a tuple is

supported as the second argument. This has the same meaning as
for isinstance(), i.e. issubclass(X, (A, B)) is equivalent
to issubclass(X, A) or issubclass(X, B). Compared to isinstance(),
this patch does not search the tuple recursively for classes, i.e.
any entry in the tuple that is not a class, will result in a
TypeError.

This closes SF patch #649608.

1 files changed, 7 insertions, 0 deletions

diff --git a/Objects/classobject.c b/Objects/classobject.c
index f7b442a80a..f3b98733de 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -487,6 +487,13 @@ PyClass_IsSubclass(PyObject *class, PyObject *base)
 	PyClassObject *cp;
 	if (class == base)
 		return 1;
+	if (PyTuple_Check(base)) {
+		n = PyTuple_GET_SIZE(base);
+		for (i = 0; i < n; i++) {
+			if (class == PyTuple_GET_ITEM(base, i))
+				return 1;
+		}
+	}
 	if (class == NULL || !PyClass_Check(class))
 		return 0;
 	cp = (PyClassObject *)class;