From e42b23ebe26e08595e1fe70ff474459e4de0bf64 Mon Sep 17 00:00:00 2001
From: John Okely <john@moodle.com>
Date: Fri, 12 Feb 2016 14:04:57 +0800
Subject: [PATCH] MDL-50218 lti: Return empty grade when none exists

---
 mod/lti/servicelib.php | 9 +++------
 mod/lti/upgrade.txt    | 5 +++++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/mod/lti/servicelib.php b/mod/lti/servicelib.php
index 438cea2d1cf..df21b61e058 100644
--- a/mod/lti/servicelib.php
+++ b/mod/lti/servicelib.php
@@ -217,14 +217,11 @@ function lti_read_grade($ltiinstance, $userid) {
     if (!empty($ltigrade) && isset($grades) && isset($grades->items[0]) && is_array($grades->items[0]->grades)) {
         foreach ($grades->items[0]->grades as $agrade) {
             $grade = $agrade->grade;
-            $grade = $grade / $ltigrade;
-            break;
+            if (isset($grade)) {
+                return $grade / $ltigrade;
+            }
         }
     }
-
-    if (isset($grade)) {
-        return $grade;
-    }
 }
 
 function lti_delete_grade($ltiinstance, $userid) {
diff --git a/mod/lti/upgrade.txt b/mod/lti/upgrade.txt
index 501cb4c2fbb..7b15886aa41 100644
--- a/mod/lti/upgrade.txt
+++ b/mod/lti/upgrade.txt
@@ -1,5 +1,10 @@
 This files describes API changes in the lti code.
 
+=== 3.1 ===
+
+* When requesting a grade from the outcome service, and empty grade will now be returned as
+  an empty grade in accordance with the spec. Previously a grade of 0 would be returned.
+
 === 3.0 ===
 
 * Function lti_view (locallib.php) was renamed to lti_launch_tool.