From c9d9703a042083d929657adb8bc1876cfe6204da Mon Sep 17 00:00:00 2001
From: PMKuipers <pm@miqra.nl>
Date: Fri, 1 Dec 2023 11:12:21 +0100
Subject: [PATCH] Bufgix where checking page progress on an empty page  would
 result in division by sero

---
 classes/studyplan.php     | 19 +++++++++++++------
 classes/studyplanpage.php |  7 ++++++-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/classes/studyplan.php b/classes/studyplan.php
index f2ffe4b..19a77a4 100644
--- a/classes/studyplan.php
+++ b/classes/studyplan.php
@@ -629,11 +629,15 @@ class studyplan {
         $progress = 0;
         $pages = $this->pages();
         foreach ($pages as $p) {
-            $progress += $p->scanuserprogress($userid);
+            $prg = $p->scanuserprogress($userid);
+            $progress += $prg;
         }
         // Now average it out over the amount of pages
-        $progress = $progress / count($pages);
-        return $progress;
+        if (count($pages) > 0 ) {
+            return $progress / count($pages);
+        } else {
+            return 0;
+        }
     }
 
     /**
@@ -642,7 +646,10 @@ class studyplan {
      * @return array Webservice data model
      */
     public function user_model($userid) {
-
+        $progress = $this->scanuserprogress($userid);
+        if (is_nan($progress)) {
+            $progress = 0;
+        }
         $model = [
             'id' => $this->r->id,
             'userid' => $userid,
@@ -652,7 +659,7 @@ class studyplan {
             'descriptionformat' => $this->r->descriptionformat,
             'icon' => $this->icon(),
             'idnumber' => $this->r->idnumber,
-            'progress' => $this->scanuserprogress($userid),
+            'progress' => $progress,
             'pages' => [],
             'aggregation_info' => $this->aggregator->basic_model(),
         ];
@@ -865,7 +872,7 @@ class studyplan {
         $sql = "SELECT COUNT(i.id)
                 FROM {local_treestudyplan}
                 INNER JOIN {local_treestudyplan_line} l ON p.id = l.studyplan_id
-                INNER JOIN {local_treestudyplan_item} i ON l.id = i.line_id
+                 {local_treestudyplan_item} i ON l.id = i.line_id
                 WHERE p.id = :planid
                    AND i.course_id = :courseid";
         $count = $DB->get_field_sql($sql, ["courseid" => $courseid, "planid" => $this->id]);
diff --git a/classes/studyplanpage.php b/classes/studyplanpage.php
index 106b2fd..36a706c 100644
--- a/classes/studyplanpage.php
+++ b/classes/studyplanpage.php
@@ -405,7 +405,12 @@ class studyplanpage {
                 }
             }
         }
-        return ($completed/$courses);
+        if ( $courses > 0 ) {
+            return ($completed/$courses);
+        } else {
+            return 0;
+        }
+
     }
 
     /**