Change issubclass() so that recursive tuples (directly or indirectly

containing class objects) are allowed as the second argument.
This makes issubclass() more similar to isinstance() where recursive
tuples are allowed too.

diff --git a/Lib/test/test_isinstance.py b/Lib/test/test_isinstance.py
index 1bb09a6edc353f695712a1fdb38bbd0db503f778..5a19387ab9c3926bf05f6791afc59c7ace353049 100644 (file)
--- a/Lib/test/test_isinstance.py
+++ b/Lib/test/test_isinstance.py
@@ -165,6 +165,13 @@ class Super:
 class Child(Super):
     pass
 
+# new-style classes
+class NewSuper(object):
+    pass
+
+class NewChild(NewSuper):
+    pass
+
 
 \f
 class TestIsInstanceIsSubclass(unittest.TestCase):
@@ -225,7 +232,17 @@ class TestIsInstanceIsSubclass(unittest.TestCase):
         self.assertEqual(False, issubclass(Super, (Child,)))
         self.assertEqual(True, issubclass(Super, (Child, Super)))
         self.assertEqual(False, issubclass(Child, ()))
-        self.assertRaises(TypeError, issubclass, Child, ((Child,),))
+        self.assertEqual(True, issubclass(Super, (Child, (Super,))))
+
+        self.assertEqual(True, issubclass(NewChild, (NewChild,)))
+        self.assertEqual(True, issubclass(NewChild, (NewSuper,)))
+        self.assertEqual(False, issubclass(NewSuper, (NewChild,)))
+        self.assertEqual(True, issubclass(NewSuper, (NewChild, NewSuper)))
+        self.assertEqual(False, issubclass(NewChild, ()))
+        self.assertEqual(True, issubclass(NewSuper, (NewChild, (NewSuper,))))
+
+        self.assertEqual(True, issubclass(int, (long, (float, int))))
+        self.assertEqual(True, issubclass(str, (unicode, (Child, NewChild, basestring))))
 
 
 

diff --git a/Objects/abstract.c b/Objects/abstract.c
index 47d2f31dd7f1da99131b219226f70888e34e1e54..8389774e2fa66242c2de1891cd3cf89227314e25 100644 (file)
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2021,11 +2021,11 @@ PyObject_IsSubclass(PyObject *derived, PyObject *cls)
                        int i;
                        int n = PyTuple_GET_SIZE(cls);
                        for (i = 0; i < n; ++i) {
-                               if (!check_class(PyTuple_GET_ITEM(cls, i),
-                                               "issubclass() arg 2 must be a class"
-                                               " or tuple of classes"))
-                                       return -1;
+                               retval = PyObject_IsSubclass(derived, PyTuple_GET_ITEM(cls, i));
+                               if (retval != 0) /* either found it, or got an error */
+                                       return retval;
                        }
+                       return 0;
                }
                else {
                        if (!check_class(cls,

diff --git a/Objects/classobject.c b/Objects/classobject.c
index f3b98733de02e00f975a67112b33215239504569..5234a658a248e78da1509aaa85c4965ccbb07577 100644 (file)
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -490,9 +490,10 @@ PyClass_IsSubclass(PyObject *class, PyObject *base)
        if (PyTuple_Check(base)) {
                n = PyTuple_GET_SIZE(base);
                for (i = 0; i < n; i++) {
-                       if (class == PyTuple_GET_ITEM(base, i))
+                       if (PyClass_IsSubclass(class, PyTuple_GET_ITEM(base, i)))
                                return 1;
                }
+               return 0;
        }
        if (class == NULL || !PyClass_Check(class))
                return 0;