Fixed bug in Base __getattro__ that caused __of__ to be missed in

instances of instances of subclasses (meta classes) of ExtensionClass.

lib/python/ExtensionClass/_ExtensionClass.c

@@ -142,7 +142,8 @@ Base_getattro(PyObject *obj, PyObject *name)
                              If the tp_descr_get of res is of_get, 
                              then call it. */
 
-                          if (res->ob_type->ob_type == &ExtensionClassType
+                          if (PyObject_TypeCheck(res->ob_type,
+                                                     &ExtensionClassType)
                               && res->ob_type->tp_descr_get != NULL)
                             res = res->ob_type->tp_descr_get(
                                                  res, obj, 

lib/python/ExtensionClass/tests.py

@@ -709,6 +709,34 @@ def test_inheriting___doc__():
 
     """
 
+def test___of___w_metaclass_instance():
+    """When looking for extension class instances, need to handle meta classes
+
+    >>> class C(Base):
+    ...     pass
+
+    >>> class O(Base):
+    ...     def __of__(self, parent):
+    ...         print '__of__ called on an O'
+
+    >>> class M(ExtensionClass):
+    ...     pass
+
+    >>> class X:
+    ...     __metaclass__ = M
+    ...     
+
+    >>> class S(X, O):
+    ...     pass
+
+    >>> c = C()
+    >>> c.s = S()
+    >>> c.s
+    __of__ called on an O
+
+    """
+
+
 from doctest import DocTestSuite
 import unittest