Cannot transition from submenu back to main menu with empty superusers

[Robert Kliewer]

I am running grub in such a way that only menu/submenu entries may be
executed by a user (command line and entry editing are disabled).  I have
'superusers' set to blank (""), all menu/submenu entries have the
'--unrestricted' parameter, and I am exporting the 'superusers' so that the
security posture carries over to the submenu.  However, when I press escape
in a submenu I get the password prompt as I would if I were trying to use
the command line or edit an entry and cannot get back to the original
menu.  Any help would be appreciated.  Thanks.

Rob