fix strange errors when setting attributes on tracebacks #4034
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 1ea586f..c8cf71b 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -604,7 +604,17 @@
 int _PyFrame_Init()
 {
 	builtin_object = PyString_InternFromString("__builtins__");
-	return (builtin_object != NULL);
+	if (builtin_object == NULL)
+		return 0;
+	/* 
+	   Traceback objects are not created the normal way (through calling the
+	   type), so PyType_Ready has to be called here.
+	*/
+	if (PyType_Ready(&PyTraceBack_Type)) {
+		Py_DECREF(builtin_object);
+		return 0;
+	}
+	return 1;
 }
 
 PyFrameObject *