Escape story fields and clean story HTML with HTML Purifier.

Add HTML Purifier 4.19.1. Stories are purified when they are saved and
when they are shown.

lib/htmlpurifier-4.19.1/library/HTMLPurifier/PropertyListIterator.php

@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * Property list iterator. Do not instantiate this class directly.
+ */
+class HTMLPurifier_PropertyListIterator extends FilterIterator
+{
+
+    /**
+     * @type int
+     */
+    protected $l;
+    /**
+     * @type string
+     */
+    protected $filter;
+
+    /**
+     * @param Iterator $iterator Array of data to iterate over
+     * @param string $filter Optional prefix to only allow values of
+     */
+    public function __construct(Iterator $iterator, $filter = null)
+    {
+        parent::__construct($iterator);
+        $this->l = strlen($filter);
+        $this->filter = $filter;
+    }
+
+    /**
+     * @return bool
+     */
+    #[\ReturnTypeWillChange]
+    public function accept()
+    {
+        $key = $this->getInnerIterator()->key();
+        if (strncmp($key, $this->filter, $this->l) !== 0) {
+            return false;
+        }
+        return true;
+    }
+}
+
+// vim: et sw=4 sts=4