From: Walter Dörwald <walter@livinglogic.de>
Date: Thu, 12 Dec 2002 19:14:08 +0000 (+0000)
Subject: Change issubclass() so that recursive tuples (directly or indirectly
X-Git-Tag: v2.3c1~3045
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7e5c6a02eba1a6f5e93bfa1241ceff39bec9f3c9;p=thirdparty%2FPython%2Fcpython.git

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 1bb09a6edc35..5a19387ab9c3 100644
--- 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
+
 
 
 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 47d2f31dd7f1..8389774e2fa6 100644
--- 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 f3b98733de02..5234a658a248 100644
--- 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;