From 10d480aefc28fd4e93af30cc5ed5a503aa3a1c61 Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Wed, 21 Sep 2016 16:09:25 +0800
Subject: [PATCH] MDL-54802 mod_quiz: Add validation to require passing grade
 greater than 0

This commit adds a form validation to prevent the creation of quizzes
using zero or null grade to pass when using require passing grade.
---
 mod/quiz/db/upgrade.php   | 22 ++++++++++++++++++++++
 mod/quiz/lang/en/quiz.php |  1 +
 mod/quiz/mod_form.php     |  7 +++++++
 mod/quiz/version.php      |  2 +-
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/mod/quiz/db/upgrade.php b/mod/quiz/db/upgrade.php
index f42c0072f83..3483107af61 100644
--- a/mod/quiz/db/upgrade.php
+++ b/mod/quiz/db/upgrade.php
@@ -193,5 +193,27 @@ function xmldb_quiz_upgrade($oldversion) {
     // Moodle v3.1.0 release upgrade line.
     // Put any upgrade step following this.
 
+    if ($oldversion < 2016052301) {
+        // Find quizzes with the combination of require passing grade and grade to pass 0.
+        $quizzes = $DB->get_records_sql("
+            SELECT gi.id, gi.iteminstance
+		      FROM {quiz} q
+        INNER JOIN {course_modules} cm ON q.id = cm.instance
+        INNER JOIN {grade_items} gi ON q.id = gi.iteminstance
+		     WHERE q.completionpass = 1
+               AND gi.gradepass = 0
+               AND cm.completiongradeitemnumber IS NULL");
+        if ($quizzes) {
+            foreach ($quizzes as $quiz) {
+                $DB->execute("UPDATE {course_modules}
+                                 SET completiongradeitemnumber = :gradeitemid
+                               WHERE instance = :quizid",
+                    array('gradeitemid' => $quiz->id, 'quizid' => $quiz->iteminstance));
+            }
+        }
+        // Quiz savepoint reached.
+        upgrade_mod_savepoint(true, 2016052301, 'quiz');
+    }
+
     return true;
 }
diff --git a/mod/quiz/lang/en/quiz.php b/mod/quiz/lang/en/quiz.php
index 5ce7771fe60..6cdd6a25ab1 100644
--- a/mod/quiz/lang/en/quiz.php
+++ b/mod/quiz/lang/en/quiz.php
@@ -396,6 +396,7 @@ $string['grademethod_help'] = 'When multiple attempts are allowed, the following
 * Last attempt (all other attempts are ignored)';
 $string['gradesdeleted'] = 'Quiz grades deleted';
 $string['gradesofar'] = '{$a->method}: {$a->mygrade} / {$a->quizgrade}.';
+$string['gradetopassnotset'] = 'This quiz does not have a grade to pass set so you cannot use this option. Please use the require grade setting instead.';
 $string['gradingdetails'] = 'Marks for this submission: {$a->raw}/{$a->max}.';
 $string['gradingdetailsadjustment'] = 'With previous penalties this gives <strong>{$a->cur}/{$a->max}</strong>.';
 $string['gradingdetailspenalty'] = 'This submission attracted a penalty of {$a}.';
diff --git a/mod/quiz/mod_form.php b/mod/quiz/mod_form.php
index a768e975149..d2938baf8f8 100644
--- a/mod/quiz/mod_form.php
+++ b/mod/quiz/mod_form.php
@@ -533,6 +533,13 @@ class mod_quiz_mod_form extends moodleform_mod {
             }
         }
 
+        if (array_key_exists('completion', $data) && $data['completion'] == COMPLETION_TRACKING_AUTOMATIC) {
+            // Show an error if require passing grade was selected and the grade to pass was setted to 0.
+            if ($data['completionpass'] == 1 && (empty($data['gradepass']) || grade_floatval($data['gradepass']) == 0)) {
+                $errors['gradepass'] = get_string('gradetopassnotset', 'quiz');
+            }
+        }
+
         // Check the boundary value is a number or a percentage, and in range.
         $i = 0;
         while (!empty($data['feedbackboundaries'][$i] )) {
diff --git a/mod/quiz/version.php b/mod/quiz/version.php
index a2ce9496e4c..4bb9aee6dec 100644
--- a/mod/quiz/version.php
+++ b/mod/quiz/version.php
@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2016052300;
+$plugin->version   = 2016052301;
 $plugin->requires  = 2016051900;
 $plugin->component = 'mod_quiz';
 $plugin->cron      = 60;