Revert "remove htmlpurifier"

This reverts commit c21a462d52.

lib/htmlpurifier/library/HTMLPurifier/AttrDef/HTML/Pixels.php

@@ -0,0 +1,48 @@
+<?php
+
+/**
+ * Validates an integer representation of pixels according to the HTML spec.
+ */
+class HTMLPurifier_AttrDef_HTML_Pixels extends HTMLPurifier_AttrDef
+{
+
+    protected $max;
+
+    public function __construct($max = null) {
+        $this->max = $max;
+    }
+
+    public function validate($string, $config, $context) {
+
+        $string = trim($string);
+        if ($string === '0') return $string;
+        if ($string === '')  return false;
+        $length = strlen($string);
+        if (substr($string, $length - 2) == 'px') {
+            $string = substr($string, 0, $length - 2);
+        }
+        if (!is_numeric($string)) return false;
+        $int = (int) $string;
+
+        if ($int < 0) return '0';
+
+        // upper-bound value, extremely high values can
+        // crash operating systems, see <http://ha.ckers.org/imagecrash.html>
+        // WARNING, above link WILL crash you if you're using Windows
+
+        if ($this->max !== null && $int > $this->max) return (string) $this->max;
+
+        return (string) $int;
+
+    }
+
+    public function make($string) {
+        if ($string === '') $max = null;
+        else $max = (int) $string;
+        $class = get_class($this);
+        return new $class($max);
+    }
+
+}
+
+// vim: et sw=4 sts=4