Ticket #23668: 23668.4.patch

src/wp-includes/taxonomy.php

@@ -352 +352 @@
         }
 
         if ( false !== $args['rewrite'] && ( is_admin() || '' != get_option( 'permalink_structure' ) ) ) {
-                if ( ! is_array( $args['rewrite'] ) )
-                        $args['rewrite'] = array();
+                $args['rewrite'] = wp_parse_args( $args['rewrite'], array(
+                        'with_front' => true,
+                        'hierarchical' => false,
+                        'ep_mask' => EP_NONE,
+                ) );
 
                 if ( empty( $args['rewrite']['slug'] ) )
                         $args['rewrite']['slug'] = sanitize_title_with_dashes( $taxonomy );
 
-                $args['rewrite'] = array_merge( array(
-                        'with_front' => true,
-                        'hierarchical' => false,
-                        'ep_mask' => EP_NONE,
-                ), $args['rewrite'] );
-
                 if ( $args['hierarchical'] && $args['rewrite']['hierarchical'] )
                         $tag = '(.+?)';
                 else