This is fixed for next build. Thank you everyone for all the detailed information. External menu items should properly output and function now when they've a bugged component_id column. Note this affects all core Joomla components as well and is easy to replicate. Simply create an internal menu item to the component in question then change it to external and the component_id remains in the database causing the router check of component != com_COMPONENT to fail to catch the external usage.