Index: canonical.php
===================================================================
--- canonical.php	(revision 10437)
+++ canonical.php	(working copy)
@@ -279,7 +279,7 @@
 			$redirect_url .= '?' . $redirect['query'];
 	}
 
-	if ( !$redirect_url || $redirect_url == $requested_url )
+	if ( $redirect_url == $requested_url )
 		return false;
 
 	// Note that you can use the "redirect_canonical" filter to cancel a canonical redirect for whatever reason by returning FALSE