From 7e0551fc4515211577a0a4fee2e647ae2d176ea5 Mon Sep 17 00:00:00 2001
From: Jean-Michel Vedrine <vedrine@vedrine.org>
Date: Sat, 7 Feb 2015 17:40:12 +0100
Subject: [PATCH] MDL-48880 mod_lesson: clean lesson_branch when a page is
 deleted

---
 .../moodle2/restore_lesson_stepslib.php       | 19 ++++++++++++++++-
 mod/lesson/db/upgrade.php                     | 21 +++++++++++++++++++
 mod/lesson/locallib.php                       |  2 ++
 mod/lesson/version.php                        |  2 +-
 4 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/mod/lesson/backup/moodle2/restore_lesson_stepslib.php b/mod/lesson/backup/moodle2/restore_lesson_stepslib.php
index e96f24395e2..8edd1ff26a7 100644
--- a/mod/lesson/backup/moodle2/restore_lesson_stepslib.php
+++ b/mod/lesson/backup/moodle2/restore_lesson_stepslib.php
@@ -255,7 +255,7 @@ class restore_lesson_activity_structure_step extends restore_activity_structure_
         }
         $rs->close();
 
-        // Replay the upgrade step 2015022700
+        // Replay the upgrade step 2015030301
         // to clean lesson answers that should be plain text.
         // 1 = LESSON_PAGE_SHORTANSWER, 8 = LESSON_PAGE_NUMERICAL, 20 = LESSON_PAGE_BRANCHTABLE.
 
@@ -275,6 +275,23 @@ class restore_lesson_activity_structure_step extends restore_activity_structure_
         }
         $badanswers->close();
 
+        // Replay the upgrade step 2015032700.
+        // Delete any orphaned lesson_branch record.
+        if ($DB->get_dbfamily() === 'mysql') {
+            $sql = "DELETE {lesson_branch}
+                      FROM {lesson_branch}
+                 LEFT JOIN {lesson_pages}
+                        ON {lesson_branch}.pageid = {lesson_pages}.id
+                     WHERE {lesson_pages}.id IS NULL";
+        } else {
+            $sql = "DELETE FROM {lesson_branch}
+               WHERE NOT EXISTS (
+                         SELECT 'x' FROM {lesson_pages}
+                          WHERE {lesson_branch}.pageid = {lesson_pages}.id)";
+        }
+
+        $DB->execute($sql);
+
         // Re-map the dependency and activitylink information
         // If a depency or activitylink has no mapping in the backup data then it could either be a duplication of a
         // lesson, or a backup/restore of a single lesson. We have no way to determine which and whether this is the
diff --git a/mod/lesson/db/upgrade.php b/mod/lesson/db/upgrade.php
index 9f9376e846b..ac37e12f09e 100644
--- a/mod/lesson/db/upgrade.php
+++ b/mod/lesson/db/upgrade.php
@@ -232,5 +232,26 @@ function xmldb_lesson_upgrade($oldversion) {
         upgrade_mod_savepoint(true, 2015031500, 'lesson');
     }
 
+    if ($oldversion < 2015032700) {
+        // Delete any orphaned lesson_branch record.
+        if ($DB->get_dbfamily() === 'mysql') {
+            $sql = "DELETE {lesson_branch}
+                      FROM {lesson_branch}
+                 LEFT JOIN {lesson_pages}
+                        ON {lesson_branch}.pageid = {lesson_pages}.id
+                     WHERE {lesson_pages}.id IS NULL";
+        } else {
+            $sql = "DELETE FROM {lesson_branch}
+               WHERE NOT EXISTS (
+                         SELECT 'x' FROM {lesson_pages}
+                          WHERE {lesson_branch}.pageid = {lesson_pages}.id)";
+        }
+
+        $DB->execute($sql);
+
+        // Lesson savepoint reached.
+        upgrade_mod_savepoint(true, 2015032700, 'lesson');
+    }
+
     return true;
 }
diff --git a/mod/lesson/locallib.php b/mod/lesson/locallib.php
index f6783457a32..3525e103001 100644
--- a/mod/lesson/locallib.php
+++ b/mod/lesson/locallib.php
@@ -2033,6 +2033,8 @@ abstract class lesson_page extends lesson_base {
 
         // Then delete all the associated records...
         $DB->delete_records("lesson_attempts", array("pageid" => $this->properties->id));
+
+        $DB->delete_records("lesson_branch", array("pageid" => $this->properties->id));
         // ...now delete the answers...
         $DB->delete_records("lesson_answers", array("pageid" => $this->properties->id));
         // ..and the page itself
diff --git a/mod/lesson/version.php b/mod/lesson/version.php
index 1bd6fe51c49..ae457699415 100644
--- a/mod/lesson/version.php
+++ b/mod/lesson/version.php
@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2015032401;       // The current module version (Date: YYYYMMDDXX)
+$plugin->version   = 2015032700;       // The current module version (Date: YYYYMMDDXX)
 $plugin->requires  = 2014110400;    // Requires this Moodle version
 $plugin->component = 'mod_lesson'; // Full name of the plugin (used for diagnostics)
 $plugin->cron      = 0;