--- canonical.php.orig	2008-02-24 01:09:00.000000000 +0100
+++ canonical.php	2008-05-01 10:19:42.953125000 +0200
@@ -137,7 +137,8 @@
 
 	// www.example.com vs example.com
 	$user_home = @parse_url(get_option('home'));
-	$redirect['host'] = $user_home['host'];
+	if ( isset($user_home['host']) )
+                $redirect['host'] = $user_home['host'];
 
 	// Handle ports
 	if ( isset($user_home['port']) )