menu cannot be deleted when redirecting parameter is present

Confirmed using 7.22. Steps to reproduce;

1. Create a menu
2. Move the menus block to a sidebar or similar
3. Visit a page showing the block, open the contextual links (gear icon), and choose 'edit menu'.
   At this time, the url is admin/structure/menu/manage/menu-MYMENU/edit?destination=PAGEURL
4. Press delete. You are redirected back to page (PAGEURL), and menu is not deleted.

If you visit admin/structure/menu/manage/menu-MYMENU/edit and press delete, you are taken to a delete menu confirmation form at admin/structure/menu/manage/menu-MYMENU/delete. The two redirects must be conflicting.

Did a bit of investigating. This page describes the problem https://api.drupal.org/api/drupal/includes!form.inc/function/drupal_redirect_form/7

If none of the above conditions has prevented redirection, then the redirect is accomplished by calling drupal_goto(), passing in the value of $form_state['redirect'] if it is set, or the current path if it is not. drupal_goto() preferentially uses the value of $_GET['destination'] (the 'destination' URL query string) if it is present, so this will override any values set by $form_state['redirect'].

With this is mind, I believe replacing menu_custom_delete_submit(), which is in menu.admin.inc, with the following code will solve the problem and maintain the original redirect.

function menu_custom_delete_submit($form, &$form_state) {

  if (isset($_GET['destination'])) {
    $form_state['redirect'] = array(
      'admin/structure/menu/manage/' . $form_state['values']['menu_name'] . '/delete',
      array(
        'query' => array(
          'destination' => $_GET['destination'],
        ),
      ),
    );
    unset($_GET['destination']);
  }
  else {
    $form_state['redirect'] = 'admin/structure/menu/manage/' . $form_state['values']['menu_name'] . '/delete';
  }

}

I am unable to create a patch at the moment...