From 5ce516a3a0cd0d9d2b14a7caec0f762252aa9b50 Mon Sep 17 00:00:00 2001
From: Calen Pennington <calen.pennington@gmail.com>
Date: Thu, 6 Sep 2012 15:23:19 -0400
Subject: [PATCH] Clamp progress to be greater than zero

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

diff --git a/common/lib/xmodule/xmodule/progress.py b/common/lib/xmodule/xmodule/progress.py
index af47f50fd7..7adbb02646 100644
--- a/common/lib/xmodule/xmodule/progress.py
+++ b/common/lib/xmodule/xmodule/progress.py
@@ -42,6 +42,9 @@ class Progress(object):
         if a > b:
             a = b
 
+        if a < 0:
+            a = 0
+
         if b <= 0:
             raise ValueError('fraction a/b = {0}/{1} must have b > 0'.format(a, b))