The parent crawler to find override children menu item is wrong

Same issue replicated here on 8.x-2.1, 8.x-2.3 and current 8.x-2.x-dev . Specific menu structure:

- menu_link_content id 71: no parent, menu_item_override_children = 0, roles A & B
- - menu_link_content id 72: parent 71, menu_item_override_children = 0, role A

With "Allow parents to override children" ticked, getOverridingParent() incorrectly returns the parent (id 71) here, resulting in the item incorrectly being shown to role B.

Patch #3 fixes the error here for this case.

@davej thank you for the testing and information on how to replicate.

When I next have time to work on this I would like to create a failing test to confirm and make sure that the bug doesn't work it's way back in to the module in the future.

Thanks all! I've also added a test for this case.

Automatically closed - issue fixed for 2 weeks with no activity.