From f63dec4bb2a6148ae0ea56e98af970aa2ed67505 Mon Sep 17 00:00:00 2001
From: Frederic Massart <fred@moodle.com>
Date: Thu, 18 Dec 2014 16:32:52 +0800
Subject: [PATCH] MDL-43679 core: Never use HTTP redirect when the user agent
 is MS Word

---
 lib/weblib.php | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/weblib.php b/lib/weblib.php
index c843fa2e2b3..8fb28a643a0 100644
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -2551,6 +2551,16 @@ function redirect($url, $message='', $delay=-1) {
             break;
         }
 
+        if (core_useragent::is_msword()) {
+            // Clicking a URL from MS Word sends a request to the server without cookies. If that
+            // causes a redirect Word will open a browser pointing the new URL. If not, the URL that
+            // was clicked is opened. Because the request from Word is without cookies, it almost
+            // always results in a redirect to the login page, even if the user is logged in in their
+            // browser. This is not what we want, so prevent the redirect for requests from Word.
+            $debugdisableredirect = true;
+            break;
+        }
+
         if (empty($CFG->debugdisplay) or empty($CFG->debug)) {
             // No errors should be displayed.
             break;