Use is_singular in url_to_postid(). See #15771

git-svn-id: http://svn.automattic.com/wordpress/trunk@16877 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/rewrite.php

@@ -337,7 +337,7 @@ function url_to_postid($url) {
 
 			// Do the query
 			$query = new WP_Query($query);
-			if ( !empty($query->posts) && ($query->is_single || $query->is_page) )
+			if ( !empty($query->posts) && $query->is_singular )
 				return $query->post->ID;
 			else
 				return 0;