Index: modules/filter/filter.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/filter/filter.module,v
retrieving revision 1.282
diff -u -p -r1.282 filter.module
--- modules/filter/filter.module	26 Aug 2009 10:28:45 -0000	1.282
+++ modules/filter/filter.module	27 Aug 2009 07:28:23 -0000
@@ -961,5 +961,12 @@ function _filter_autop($text) {
 }
 
 /**
+ * Escapes all HTML tags, so they will be visible instead of being effective.
+ */
+function _filter_html_escape($text) {
+  return trim(check_plain($text));
+}
+
+/**
  * @} End of "Standard filters".
  */