[Python-checkins] r76794 - in python/trunk: Lib/test/test_descr.py Misc/NEWS Objects/typeobject.c

[benjamin.peterson]

Author: benjamin.peterson
Date: Sun Dec 13 17:36:53 2009
New Revision: 76794

Log:
fix the ignoring of __cmp__ method on metaclasses #7491


Modified:
   python/trunk/Lib/test/test_descr.py
   python/trunk/Misc/NEWS
   python/trunk/Objects/typeobject.c

Modified: python/trunk/Lib/test/test_descr.py
==============================================================================
--- python/trunk/Lib/test/test_descr.py	(original)
+++ python/trunk/Lib/test/test_descr.py	Sun Dec 13 17:36:53 2009
@@ -1222,6 +1222,15 @@
         # This used to crash
         self.assertRaises(TypeError, MyABC.a.__set__, u, 3)
 
+    def test_metaclass_cmp(self):
+        # See bug 7491.
+        class M(type):
+            def __cmp__(self, other):
+                return -1
+        class X(object):
+            __metaclass__ = M
+        self.assertTrue(X < M)
+
     def test_dynamics(self):
         # Testing class attribute propagation...
         class D(object):

Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Sun Dec 13 17:36:53 2009
@@ -12,6 +12,8 @@
 Core and Builtins
 -----------------
 
+- Issue #7491: Metaclass's __cmp__ method was ignored.
+
 - Issue #7466: segmentation fault when the garbage collector is called
   in the middle of populating a tuple.  Patch by Florent Xicluna.
 

Modified: python/trunk/Objects/typeobject.c
==============================================================================
--- python/trunk/Objects/typeobject.c	(original)
+++ python/trunk/Objects/typeobject.c	Sun Dec 13 17:36:53 2009
@@ -628,7 +628,11 @@
 	int c;
 
 	/* Make sure both arguments are types. */
-	if (!PyType_Check(v) || !PyType_Check(w)) {
+	if (!PyType_Check(v) || !PyType_Check(w) ||
+	    /* If there is a __cmp__ method defined, let it be called instead
+	       of our dumb function designed merely to warn.  See bug
+	       #7491. */
+	    Py_TYPE(v)->tp_compare || Py_TYPE(w)->tp_compare) {
 		result = Py_NotImplemented;
 		goto out;
 	}