From 734fb0f01547e590ebe270bd47334f71d4c9267d 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 ca0e48b89d1..ddfa6dbcfbf 100644
--- a/mod/lesson/db/upgrade.php
+++ b/mod/lesson/db/upgrade.php
@@ -387,5 +387,24 @@ function xmldb_lesson_upgrade($oldversion) {
     // Moodle v3.1.0 release upgrade line.
     // Put any upgrade step following this.
 
+    if ($oldversion < 2016052301) {
+
+        // 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, 2016052301, 'lesson');
+    }
+
     return true;
 }
diff --git a/mod/lesson/locallib.php b/mod/lesson/locallib.php
index e25fd634f09..d3679f13d4c 100644
--- a/mod/lesson/locallib.php
+++ b/mod/lesson/locallib.php
@@ -2291,6 +2291,15 @@ 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
@@ -2310,8 +2319,6 @@ 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 699335960c2..5a5d99b947f 100644
--- a/mod/lesson/version.php
+++ b/mod/lesson/version.php
@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2016052300;       // The current module version (Date: YYYYMMDDXX)
+$plugin->version   = 2016052301;       // The current module version (Date: YYYYMMDDXX)
 $plugin->requires  = 2016051900;    // Requires this Moodle version
 $plugin->component = 'mod_lesson'; // Full name of the plugin (used for diagnostics)
 $plugin->cron      = 0;