Index: wp-includes/class-wp.php
===================================================================
--- wp-includes/class-wp.php	(revision 38507)
+++ wp-includes/class-wp.php	(working copy)
@@ -120,6 +120,9 @@
 	function parse_request($extra_query_vars = '') {
 		global $wp_rewrite;
 
+		if ( ! apply_filters( 'do_parse_request', true, $this, $extra_query_vars ) )
+			return;
+
 		$this->query_vars = array();
 		$post_type_query_vars = array();