Logout process on Shibboleth IdP v4.2.

[Cantor, Scott]

>    I'd like to clarify which version is called the modern version of the IdP.

I meant V3+, because V2 was a totally different code/design.

>    If it's in version 3.4., then there is a solution to give us the same result in
> version 4.2.1.

They are largely identical save for some adjustments to the templates to allow some additional options for the UI, but none of them support a return parameter formally.

>  Then, what should I configure Logout Setting?

I have addressed ways to hack in support for things like this in the past on list but I have never attempted it so I have no examples to share. If you honestly believe it worked before, then it would work now with at most trivial differences.

-- Scott