From 8782b691a582c2d26fad5531f938e1def30682e7 Mon Sep 17 00:00:00 2001
From: Adrian Greeve <adrian@moodle.com>
Date: Thu, 13 Jul 2017 12:30:35 +0800
Subject: [PATCH] MDL-57649 mod_lesson: Delete answer files correctly.

The files associated with answers and responses were
not being deleted due to the fact that the wrong itemid
was being used.
---
 mod/lesson/db/upgrade.php | 19 +++++++++++++++++++
 mod/lesson/locallib.php   | 11 +++++++++--
 mod/lesson/version.php    |  2 +-
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/mod/lesson/db/upgrade.php b/mod/lesson/db/upgrade.php
index d12bb8ed32c..f4afd8c496e 100644
--- a/mod/lesson/db/upgrade.php
+++ b/mod/lesson/db/upgrade.php
@@ -390,5 +390,24 @@ function xmldb_lesson_upgrade($oldversion) {
     // Automatically generated Moodle v3.2.0 release upgrade line.
     // Put any upgrade step following this.
 
+    if ($oldversion < 2016120501) {
+
+        // Delete orphaned lesson answer and response files.
+        $sql = "SELECT DISTINCT f.*
+                  FROM {files} f
+             LEFT JOIN {lesson_answers} la ON f.itemid = la.id
+                 WHERE component = :component
+                   AND la.id IS NULL";
+
+        $orphanedfiles = $DB->get_recordset_sql($sql, array('component' => 'mod_lesson'));
+        $fs = get_file_storage();
+        foreach ($orphanedfiles as $file) {
+            $fs->delete_area_files($file->contextid, $file->component, $file->filearea, $file->itemid);
+        }
+        $orphanedfiles->close();
+
+        upgrade_mod_savepoint(true, 2016120501, 'lesson');
+    }
+
     return true;
 }
diff --git a/mod/lesson/locallib.php b/mod/lesson/locallib.php
index 28ce430b848..b70669ff845 100644
--- a/mod/lesson/locallib.php
+++ b/mod/lesson/locallib.php
@@ -2388,6 +2388,15 @@ abstract class lesson_page extends lesson_base {
         $DB->delete_records("lesson_attempts", array("pageid" => $this->properties->id));
 
         $DB->delete_records("lesson_branch", array("pageid" => $this->properties->id));
+
+        // Delete files related to answers and responses.
+        if ($answers = $DB->get_records("lesson_answers", array("pageid" => $this->properties->id))) {
+            foreach ($answers as $answer) {
+                $fs->delete_area_files($context->id, 'mod_lesson', 'page_answers', $answer->id);
+                $fs->delete_area_files($context->id, 'mod_lesson', 'page_responses', $answer->id);
+            }
+        }
+
         // ...now delete the answers...
         $DB->delete_records("lesson_answers", array("pageid" => $this->properties->id));
         // ..and the page itself
@@ -2407,8 +2416,6 @@ abstract class lesson_page extends lesson_base {
 
         // Delete files associated with this page.
         $fs->delete_area_files($context->id, 'mod_lesson', 'page_contents', $this->properties->id);
-        $fs->delete_area_files($context->id, 'mod_lesson', 'page_answers', $this->properties->id);
-        $fs->delete_area_files($context->id, 'mod_lesson', 'page_responses', $this->properties->id);
 
         // repair the hole in the linkage
         if (!$this->properties->prevpageid && !$this->properties->nextpageid) {
diff --git a/mod/lesson/version.php b/mod/lesson/version.php
index 3f0759f1c37..4b0e1585426 100644
--- a/mod/lesson/version.php
+++ b/mod/lesson/version.php
@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2016120500;     // The current module version (Date: YYYYMMDDXX)
+$plugin->version   = 2016120501;     // The current module version (Date: YYYYMMDDXX)
 $plugin->requires  = 2016112900;    // Requires this Moodle version
 $plugin->component = 'mod_lesson'; // Full name of the plugin (used for diagnostics)
 $plugin->cron      = 0;