From d18f42224c9906915725e585f8ab20291eb88cac Mon Sep 17 00:00:00 2001
From: Chris Dodge <cdodge@edx.org>
Date: Mon, 17 Dec 2012 10:41:54 -0500
Subject: [PATCH] fix crash of custom tags when running against Mongo
 datastores. Mongo's 'system' does not have a course_id attribute defined,
 which makes it asymmetric to XmlFilesystem store

---
 common/lib/xmodule/xmodule/modulestore/mongo.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/common/lib/xmodule/xmodule/modulestore/mongo.py b/common/lib/xmodule/xmodule/modulestore/mongo.py
index 19f506906c..c65c031c9a 100644
--- a/common/lib/xmodule/xmodule/modulestore/mongo.py
+++ b/common/lib/xmodule/xmodule/modulestore/mongo.py
@@ -51,6 +51,9 @@ class CachingDescriptorSystem(MakoDescriptorSystem):
         self.modulestore = modulestore
         self.module_data = module_data
         self.default_class = default_class
+        # cdodge: other Systems have a course_id attribute defined. To keep things consistent, let's
+        # define an attribute here as well, even though it's None
+        self.course_id = None
 
     def load_item(self, location):
         location = Location(location)