Ticket #15813: 15813.1.diff

wp-includes/taxonomy.php

@@ -329 +329 @@
                         $tag = '([^/]+)';
 
                 $wp_rewrite->add_rewrite_tag("%$taxonomy%", $tag, $args['query_var'] ? "{$args['query_var']}=" : "taxonomy=$taxonomy&term=");
-                $wp_rewrite->add_permastruct($taxonomy, "{$args['rewrite']['slug']}/%$taxonomy%", $args['rewrite']['with_front']);
+                $wp_rewrite->add_permastruct($taxonomy, "{$wp_rewrite->root}{$args['rewrite']['slug']}/%$taxonomy%", $args['rewrite']['with_front']);
         }
 
         if ( is_null($args['show_ui']) )