Ticket #16946: 16946.2.patch

wp-admin/menu.php

@@ -94 +94 @@
         // Check if it should be a submenu.
         if ( $ptype_obj->show_in_menu !== true )
                 continue;
-        $ptype_menu_position = is_int( $ptype_obj->menu_position ) ? $ptype_obj->menu_position : ++$_wp_last_object_menu; // If we're to use $_wp_last_object_menu, increment it first.
+        // Adjust the position if it's already occupied
+        if ( is_int( $ptype_obj->menu_position ) && ( $ptype_obj->menu_position == $_wp_last_object_menu ) ) {
+                $ptype_menu_position = $ptype_obj->menu_position;
+                $_wp_last_object_menu;
+        } elseif ( is_int( $ptype_obj->menu_position ) && isset( $menu[$ptype_obj->menu_position] ) ) {
+                $ptype_menu_position = $ptype_obj->menu_position + 1;
+        } else {
+                $ptype_menu_position = $ptype_obj->menu_position;
+        }
         $ptype_for_id = sanitize_html_class( $ptype );
 
         $menu_icon = 'dashicons-admin-post';