From f9a0425f04ee3cb18c38ed6135ca720755aa3bc3 Mon Sep 17 00:00:00 2001
From: Dan Marsden <dan@danmarsden.com>
Date: Fri, 1 Mar 2019 12:41:35 +1300
Subject: [PATCH] Fix #371 set grade to 0 if null.

---
 preferences.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/preferences.php b/preferences.php
index 24d6378..fe3e21a 100644
--- a/preferences.php
+++ b/preferences.php
@@ -70,7 +70,7 @@ switch ($att->pageparams->action) {
         $newdescription     = optional_param('newdescription', null, PARAM_TEXT);
         $newgrade           = optional_param('newgrade', 0, PARAM_RAW);
         $newstudentavailability = optional_param('newstudentavailability', null, PARAM_INT);
-        $newgrade = unformat_float($newgrade);
+        $newgrade = empty($newgrade) ? 0 : unformat_float($newgrade);
 
         $newstatus = new stdClass();
         $newstatus->attendanceid = $att->id;