A taskboard card with non visible children in its taskboard's swimlane should be considered like a solo item.
Tuleap currently does not do that which look like the swimlane is broken since you cannot move the card around and cannot change its status.
This situation can happen in at least two situations:
- children has no existence in the mapping (e.g. the child is from another project)
- children cannot be seen by the current user because of the permissions