MDL-9151 HTML Purifier cleaning support - enable switch is in experimental section

MDL-9435 Reviewved url cleaning in redirect()

lib/htmlpurifier/HTMLPurifier/AttrDef/HTML/Length.php

@@ -0,0 +1,44 @@
+<?php
+
+require_once 'HTMLPurifier/AttrDef.php';
+require_once 'HTMLPurifier/AttrDef/HTML/Pixels.php';
+
+/**
+ * Validates the HTML type length (not to be confused with CSS's length).
+ * 
+ * This accepts integer pixels or percentages as lengths for certain
+ * HTML attributes.
+ */
+
+class HTMLPurifier_AttrDef_HTML_Length extends HTMLPurifier_AttrDef_HTML_Pixels
+{
+    
+    function validate($string, $config, &$context) {
+        
+        $string = trim($string);
+        if ($string === '') return false;
+        
+        $parent_result = parent::validate($string, $config, $context);
+        if ($parent_result !== false) return $parent_result;
+        
+        $length = strlen($string);
+        $last_char = $string[$length - 1];
+        
+        if ($last_char !== '%') return false;
+        
+        $points = substr($string, 0, $length - 1);
+        
+        if (!is_numeric($points)) return false;
+        
+        $points = (int) $points;
+        
+        if ($points < 0) return '0%';
+        if ($points > 100) return '100%';
+        
+        return ((string) $points) . '%';
+        
+    }
+    
+}
+
+?>