Another comparison patch-up: comparing a type with a dynamic metatype

to one with a static metatype raised an obscure error.

Lib/test/test_descr.py

@@ -921,6 +921,13 @@ def dynamics():
     verify(L(3)*2 == 6)
     verify(L(3)*L(2) == 6)
 
+    # Test comparison of classes with dynamic metaclasses
+    class dynamicmetaclass(type):
+        __dynamic__ = 1
+    class someclass:
+        __metaclass__ = dynamicmetaclass
+    verify(someclass != object)
+
 def errors():
     if verbose: print "Testing errors..."
 

Objects/typeobject.c

@@ -2033,7 +2033,8 @@ wrap_cmpfunc(PyObject *self, PyObject *args, void *wrapped)
 
 	if (!PyArg_ParseTuple(args, "O", &other))
 		return NULL;
-	if (!PyType_IsSubtype(other->ob_type, self->ob_type)) {
+	if (other->ob_type->tp_compare != func &&
+	    !PyType_IsSubtype(other->ob_type, self->ob_type)) {
 		PyErr_Format(
 			PyExc_TypeError,
 			"%s.__cmp__(x,y) requires y to be a '%s', not a '%s'",