From 6369652f17da52b08fedee246c0c0c665da9eca6 Mon Sep 17 00:00:00 2001
From: Damyon Wiese <damyon@moodle.com>
Date: Wed, 6 Mar 2013 21:01:11 +0800
Subject: [PATCH] MDL-38173 Courselib: Improvements to the upgrade step for
 this issue.

Set the upgrade step to only run for affected versions correctly (use a
range of affected versions) and make the query to find affected sections DISTINCT.
Also rename aliases and variables to use cm and cmid.
---
 lib/db/upgrade.php | 31 +++++++++++++++----------------
 version.php        |  2 +-
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 6885aa0a85e..cd1aa1f9c80 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -1063,7 +1063,7 @@ function xmldb_main_upgrade($oldversion) {
 
     // This is checking to see if the site has been running a specific version with a bug in it
     // because this upgrade step is slow and is only needed if the site has been running with the previous patch installed.
-    if ($oldversion == 2012062504.08) {
+    if ($oldversion >= 2012062504.08 && $oldversion < 2012062504.11) {
         // Retrieve the list of course_sections as a recordset to save memory.
         // This is to fix a regression caused by MDL-37939.
         // In this case the upgrade step is fixing records where:
@@ -1074,33 +1074,32 @@ function xmldb_main_upgrade($oldversion) {
         // The syntax for the like query is looking for a value in a comma separated list.
         // It adds a comma to either site of the list and then searches for LIKE '%,id,%'.
         $sequenceconcat = $DB->sql_concat("','", 's.sequence', "','");
-        $moduleconcat = $DB->sql_concat("'%,'", 'm.id', "',%'");
-        $sql = 'SELECT
-                    s.id,
+        $moduleconcat = $DB->sql_concat("'%,'", 'cm.id', "',%'");
+        $sql = 'SELECT 
+                    DISTINCT(s.id),
                     s.course,
                     s.sequence
                 FROM
-                    {course_modules} m
+                    {course_modules} cm
                 JOIN {course_sections} s
                 ON
-                    m.course = s.course AND
-                    m.section != s.id
-                WHERE ' . $sequenceconcat . ' LIKE ' . $moduleconcat;
+                    cm.course = s.course
+                WHERE cm.section != s.id AND ' . $sequenceconcat . ' LIKE ' . $moduleconcat;
         $coursesections = $DB->get_recordset_sql($sql);
 
         foreach ($coursesections as $coursesection) {
-            // Retrieve all of the actual modules in this course and section combination to reduce DB calls
+            // Retrieve all of the actual modules in this course and section combination to reduce DB calls.
             $actualsectionmodules = $DB->get_records('course_modules',
                     array('course' => $coursesection->course, 'section' => $coursesection->id), '', 'id, section');
 
-            // Break out the current sequence so that we can compare it
+            // Break out the current sequence so that we can compare it.
             $currentsequence = explode(',', $coursesection->sequence);
             $orphanlist = array();
 
-            // Check each of the modules in the current sequence
-            foreach ($currentsequence as $module) {
-                if (!empty($module) && !isset($actualsectionmodules[$module])) {
-                    $orphanlist[] = $module;
+            // Check each of the modules in the current sequence.
+            foreach ($currentsequence as $cmid) {
+                if (!empty($cmid) && !isset($actualsectionmodules[$cmid])) {
+                    $orphanlist[] = $cmid;
                 }
             }
 
@@ -1110,7 +1109,7 @@ function xmldb_main_upgrade($oldversion) {
 
                 $DB->set_field_select('course_modules', 'section', $coursesection->id, $sql, $params);
 
-                // And clear the sectioncache and modinfo cache - they'll be regenerated on next use
+                // And clear the sectioncache and modinfo cache - they'll be regenerated on next use.
                 $course = new stdClass();
                 $course->id = $coursesection->course;
                 $course->sectioncache = null;
@@ -1121,7 +1120,7 @@ function xmldb_main_upgrade($oldversion) {
         $coursesections->close();
 
         // Main savepoint reached.
-        upgrade_main_savepoint(true, 2012062504.10);
+        upgrade_main_savepoint(true, 2012062504.11);
     }
 
     return true;
diff --git a/version.php b/version.php
index 50d5460f554..c7e113891be 100644
--- a/version.php
+++ b/version.php
@@ -30,7 +30,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 
-$version  = 2012062504.10;              // YYYYMMDD      = weekly release date of this DEV branch
+$version  = 2012062504.11;              // YYYYMMDD      = weekly release date of this DEV branch
                                         //         RR    = release increments - 00 in DEV branches
                                         //           .XX = incremental changes