From 68ef378b1bc63dcc04174272fc4cb4df750b8dac Mon Sep 17 00:00:00 2001
From: Paul Holden <pholden@greenhead.ac.uk>
Date: Thu, 13 Nov 2014 16:20:16 +0800
Subject: [PATCH] MDL-44657 forms: Form identifiers should only contain basic
 characters

---
 lib/formslib.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/formslib.php b/lib/formslib.php
index acb5db31ae8..1291d312ba9 100644
--- a/lib/formslib.php
+++ b/lib/formslib.php
@@ -211,7 +211,9 @@ abstract class moodleform {
      * @return string form identifier.
      */
     protected function get_form_identifier() {
-        return get_class($this);
+        $class = get_class($this);
+
+        return preg_replace('/[^a-z0-9_]/i', '_', $class);
     }
 
     /**