some important stuff we'll need

lib/htmlpurifier/library/HTMLPurifier/URIScheme/file.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Validates file as defined by RFC 1630 and RFC 1738.
+ */
+class HTMLPurifier_URIScheme_file extends HTMLPurifier_URIScheme {
+
+    // Generally file:// URLs are not accessible from most
+    // machines, so placing them as an img src is incorrect.
+    public $browsable = false;
+
+    // Basically the *only* URI scheme for which this is true, since
+    // accessing files on the local machine is very common.  In fact,
+    // browsers on some operating systems don't understand the
+    // authority, though I hear it is used on Windows to refer to
+    // network shares.
+    public $may_omit_host = true;
+
+    public function doValidate(&$uri, $config, $context) {
+        // Authentication method is not supported
+        $uri->userinfo = null;
+        // file:// makes no provisions for accessing the resource
+        $uri->port     = null;
+        // While it seems to work on Firefox, the querystring has
+        // no possible effect and is thus stripped.
+        $uri->query    = null;
+        return true;
+    }
+
+}
+
+// vim: et sw=4 sts=4