Expected behaviour of RETAIN_DETACH in child controllers

Given:
- ParentController with RetainViewMode.RELEASE_DETACH
- ChildController with RetainViewMode.RETAIN_DETACH

What happens:
- If PC is detached, CC.onDestroyView() is called even though it has RETAIN_DETACH set.
- This is because PC.removeHost() calls CC.detach() with "forceViewRefRemoval=true".

Questions:
- Is this on purpose?
- Is this correct because the view of PC has been destroyed and therefore the container of the CC?
- Wouldn't it be (technically) possible for conductor to NOT call CC.onDestroyView() because of RETAIN_DETACH and later reuse the initialy created view of CC instead of calling CC.onCreateView() again which effectively makes RETAIN_DETACH useless?

Currently RETAIN_DETACH on child controllers only works if all parent controllers also have RETAIN_DETACH set - which is not always desired. Actually a parent controller should not be aware of a child controller's view mode settings anyway.

Would be good to have some clarification on that. I'm probably missing something...

Thank you.

Start by reading ParentController.removeHost() and the child controller detach path, focusing on the forceViewRefRemoval=true argument and the RETAIN_DETACH lifecycle callbacks. Trace when onDestroyView() and onCreateView() are invoked for the parent and child. Done means establishing and documenting the intended behavior, or defining a scoped lifecycle change with coverage for the parent/child retention combinations.

Written by the indexing model from the issue text.