commit 5a8af29775d47cc1f0343d04d4172919972c73e7
Author: Francois Marier <francois@catalyst.net.nz>
Date:   Tue Mar 1 11:56:03 2011 +1300

    clean_html: allow namespaced IDs
    
    Based on http://htmlpurifier.org/docs/enduser-id.html
    
    Bug #725634
    
    Signed-off-by: Francois Marier <francois@catalyst.net.nz>

diff --git a/htdocs/lib/web.php b/htdocs/lib/web.php
index a942104..7320527 100644
--- a/htdocs/lib/web.php
+++ b/htdocs/lib/web.php
@@ -2549,6 +2549,11 @@ function clean_html($text, $xhtml=false) {
     $config->set('HTML.SafeObject', true);
     $config->set('Output.FlashCompat', true);
 
+    // Allow namespaced IDs
+    // see http://htmlpurifier.org/docs/enduser-id.html
+    $config->set('Attr.EnableID', true);
+    $config->set('Attr.IDPrefix', 'user_');
+
     $customfilters = array();
     if (get_config('filters')) {
         foreach (unserialize(get_config('filters')) as $filter) {