From fd14eb5c401c729d2ffa34f94870001f6f453279 Mon Sep 17 00:00:00 2001
From: Daniel Kosinski <de.kosinski@gmail.com>
Date: Thu, 26 Feb 2015 21:42:53 +0100
Subject: [PATCH] MDL-46705 admin: Check if course with same shortname already
 exists

---
 lib/adminlib.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/adminlib.php b/lib/adminlib.php
index 37da3db1b7e..c0c44656e44 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -3947,10 +3947,14 @@ class admin_setting_sitesettext extends admin_setting_configtext {
      * @return mixed true or message string
      */
     public function validate($data) {
+        global $DB;
         $cleaned = clean_param($data, PARAM_TEXT);
         if ($cleaned === '') {
             return get_string('required');
         }
+        if ($this->name ==='shortname' && $DB->record_exists('course', array('shortname' => $data))) {
+            return get_string('shortnametaken', 'error', $data);
+        }
         if ("$data" == "$cleaned") { // implicit conversion to string is needed to do exact comparison
             return true;
         } else {