Ticket #25341: 25341.diff

src/wp-includes/post-template.php

@@ -458 +458 @@
         } elseif ( is_archive() ) {
                 if ( is_post_type_archive() ) {
                         $classes[] = 'post-type-archive';
-                        $classes[] = 'post-type-archive-' . sanitize_html_class( get_query_var( 'post_type' ) );
+                        foreach ( (array) get_query_var( 'post_type' ) as $post_type )
+                                $classes[] = 'post-type-archive-' . sanitize_html_class( $post_type );
                 } else if ( is_author() ) {
                         $author = $wp_query->get_queried_object();
                         $classes[] = 'author';