From a011effb499c2ff0592fbc77c846233be81f37ec Mon Sep 17 00:00:00 2001
From: Andrew Nicols <andrew@nicols.co.uk>
Date: Tue, 9 May 2017 15:00:00 +0800
Subject: [PATCH] MDL-58857 admin: Terminate the session if a major upgrade is
 required

---
 admin/index.php  |  6 ++++++
 lib/setuplib.php | 32 +++++++++++++++++++++++++-------
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/admin/index.php b/admin/index.php
index 30ba5cb2c43..6cf7f45e91b 100644
--- a/admin/index.php
+++ b/admin/index.php
@@ -101,6 +101,12 @@ if (function_exists('opcache_invalidate')) {
 // indirectly calls the protected init() method is good here.
 core_component::get_core_subsystems();
 
+if (is_major_upgrade_required() && isloggedin()) {
+    // A major upgrade is required.
+    // Terminate the session and redirect back here before anything DB-related happens.
+    redirect_if_major_upgrade_required();
+}
+
 require_once($CFG->libdir.'/adminlib.php');    // various admin-only functions
 require_once($CFG->libdir.'/upgradelib.php');  // general upgrade/install related functions
 
diff --git a/lib/setuplib.php b/lib/setuplib.php
index 67ac2a4b6ad..9759ced0279 100644
--- a/lib/setuplib.php
+++ b/lib/setuplib.php
@@ -1388,16 +1388,34 @@ function disable_output_buffering() {
 }
 
 /**
- * Check whether a major upgrade is needed. That is defined as an upgrade that
- * changes something really fundamental in the database, so nothing can possibly
- * work until the database has been updated, and that is defined by the hard-coded
- * version number in this function.
+ * Check whether a major upgrade is needed.
+ *
+ * That is defined as an upgrade that changes something really fundamental
+ * in the database, so nothing can possibly work until the database has
+ * been updated, and that is defined by the hard-coded version number in
+ * this function.
+ *
+ * @return bool
+ */
+function is_major_upgrade_required() {
+    global $CFG;
+    $lastmajordbchanges = 2017040403.00;
+
+    $required = empty($CFG->version);
+    $required = $required || (float)$CFG->version < $lastmajordbchanges;
+    $required = $required || during_initial_install();
+    $required = $required || !empty($CFG->adminsetuppending);
+
+    return $required;
+}
+
+/**
+ * Redirect to the Notifications page if a major upgrade is required, and
+ * terminate the current user session.
  */
 function redirect_if_major_upgrade_required() {
     global $CFG;
-    $lastmajordbchanges = 2017040403.00;
-    if (empty($CFG->version) or (float)$CFG->version < $lastmajordbchanges or
-            during_initial_install() or !empty($CFG->adminsetuppending)) {
+    if (is_major_upgrade_required()) {
         try {
             @\core\session\manager::terminate_current();
         } catch (Exception $e) {