Ticket #18785: 18785.7.diff

wp-admin/includes/screen.php

@@ -466 +466 @@
                                         break;
                         }
                 }
- 
+
+                // The post_type must be registed for the taxonomy.
+                if ( $taxonomy && $post_type ) {
+                        if ( ! in_array( $taxonomy , get_object_taxonomies( $post_type ) ) )
+                                $post_type = '';
+                }
+
                 switch ( $base ) {
                         case 'post' :
                                 if ( ! $post_type )