From 7599223a1cbb0bb69a7e6cae6148685777cabdb1 Mon Sep 17 00:00:00 2001
From: Andrew Madden <andrew.madden@live.com.au>
Date: Thu, 4 Jul 2019 11:49:46 +1000
Subject: [PATCH] MDL-66032 badges: Prevent empty awarded badges criteria being
 created.

When creating or editing the awarded badges criteria, the select element should be
required to prevent empty criteria from being created. In addition, if there are
already badges created with the empty criteria, there should be not be an exception
thrown when assessing whether the criteria has been completed.
---
 badges/criteria/award_criteria_badge.php | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/badges/criteria/award_criteria_badge.php b/badges/criteria/award_criteria_badge.php
index d9bd7957dc4..ebddecf8180 100644
--- a/badges/criteria/award_criteria_badge.php
+++ b/badges/criteria/award_criteria_badge.php
@@ -112,7 +112,7 @@ class award_criteria_badge extends award_criteria {
             if ($this->id !== 0) {
                 $selected = array_keys($this->params);
             }
-            $settings = array('multiple' => 'multiple', 'size' => 20, 'class' => 'selectbadge');
+            $settings = array('multiple' => 'multiple', 'size' => 20, 'class' => 'selectbadge', 'required' => 'required');
             $mform->addElement('select', 'badge_badges', get_string('addbadge', 'badges'), $select, $settings);
             $mform->addRule('badge_badges', get_string('requiredbadge', 'badges'), 'required');
             $mform->addHelpButton('badge_badges', 'addbadge', 'badges');
@@ -243,7 +243,6 @@ class award_criteria_badge extends award_criteria {
         if ($this->method == BADGE_CRITERIA_AGGREGATION_ANY) {
             // User has received ANY of the required badges.
             $join = " LEFT JOIN {badge_issued} bi2 ON bi2.userid = u.id";
-            $where = "AND (";
             $i = 0;
             foreach ($this->params as $param) {
                 if ($i == 0) {
@@ -254,7 +253,10 @@ class award_criteria_badge extends award_criteria {
                 $params['badgeid'.$i] = $param['badge'];
                 $i++;
             }
-            $where .= ") ";
+            // MDL-66032 Do not create expression if there are no badges in criteria.
+            if (!empty($where)) {
+                $where = ' AND (' . $where . ') ';
+            }
             return array($join, $where, $params);
         } else {
             // User has received ALL of the required badges.