Don't access PyClasssObject in Pyston directly. Use PyObject_GetAttrWrapper instead.

In Pyston, PyClassObject is just an opaque pointer. Don't access it directly.
Use PyObject_GetAttrWrapper which provided by Pyston:

-        d = ((PyClassObject *)cls)->cl_dict;
+        d = PyObject_GetAttrWrapper(cls);

src/ExtensionClass/_ExtensionClass.c

@@ -471,14 +471,15 @@ inheritedAttribute(PyTypeObject *self, PyObject *name)
       if (PyType_Check(cls))
         d = ((PyTypeObject *)cls)->tp_dict;
       else if (PyClass_Check(cls))
-        d = ((PyClassObject *)cls)->cl_dict;
+        // d = ((PyClassObject *)cls)->cl_dict;
+        d = PyObject_GetAttrWrapper(cls);
       else
         /* Unrecognized thing, punt */
         d = NULL;
-      
+
       if ((d == NULL) || (PyDict_GetItem(d, name) == NULL))
         continue;
-                    
+
       return PyObject_GetAttr(cls, name);
     }
 
@@ -876,25 +877,32 @@ PyECMethod_New_(PyObject *callable, PyObject *inst)
 {
   if (! PyExtensionInstance_Check(inst))
     {
-      PyErr_SetString(PyExc_TypeError, 
+      PyErr_SetString(PyExc_TypeError,
                       "Can't bind non-ExtensionClass instance.");
       return NULL;
     }
 
   if (PyMethod_Check(callable))
     {
-      if (callable->ob_refcnt == 1)
-        {
-          Py_XDECREF(((PyMethodObject*)callable)->im_self);
-          Py_INCREF(inst);
-          ((PyMethodObject*)callable)->im_self = inst;
-          Py_INCREF(callable);
-          return callable;
-        }
-      else
+      // if (callable->ob_refcnt == 1)
+        // {
+          // Pyston change:
+          // Py_XDECREF(((PyMethodObject*)callable)->im_self);
+          // Py_XDECREF(PyMethod_Self((PyObject *)callable));
+          // Py_INCREF(inst);
+          // ((PyMethodObject*)callable)->im_self = inst;
+          // PyMethod_Self((PyObject *)callable) = inst;
+          // Py_INCREF(callable);
+          // return callable;
+        // }
+      // else
+        // Pyston change:
         return callable->ob_type->tp_descr_get(
-                   callable, inst, 
-                   ((PyMethodObject*)callable)->im_class);
+                  callable, inst,
+                  PyMethod_Class((PyObject *)callable));
+        // return callable->ob_type->tp_descr_get(
+        //           callable, inst,
+        //           ((PyMethodObject*)callable)->im_class);
     }
   else
     return PyMethod_New(callable, inst, (PyObject*)(ECBaseType));