From e2a84477779a864b2aa051b9ab9d7bb06234aab1 Mon Sep 17 00:00:00 2001
From: Andrew Davis <andrew@affinitysoftware.net>
Date: Wed, 11 Aug 2010 07:28:57 +0000
Subject: [PATCH] gradebook MDL-19070 Added a guard to protect against a
 potential error

---
 grade/edit/tree/lib.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/grade/edit/tree/lib.php b/grade/edit/tree/lib.php
index cd4b953f8a0..3bded5651a5 100755
--- a/grade/edit/tree/lib.php
+++ b/grade/edit/tree/lib.php
@@ -793,7 +793,12 @@ class grade_edit_tree_column_range extends grade_edit_tree_column {
             $grademax = format_float($item->grademax, $item->get_decimals());
         } elseif ($item->gradetype == GRADE_TYPE_SCALE) {
             $scale = $DB->get_record('scale', array('id' => $item->scaleid));
-            $scale_items = explode(',', $scale->scale);
+            $scale_items = null;
+            if (empty($scale)) { //if the item is using a scale that's been removed
+                $scale_items = array();
+            } else {
+                $scale_items = explode(',', $scale->scale);
+            }
             $grademax = end($scale_items) . ' (' . count($scale_items) . ')';
         } elseif ($item->is_external_item()) {
             $grademax = format_float($item->grademax, $item->get_decimals());