This:

https://softwareengineering.stackexchange.com/questions/40296/what-is-the-best-java-programming-book-out-there-for-starters

Was closed as a duplicate. The question it was allegedly a duplicate of has been deleted.

Needless to say, this is a tad useless.

Do we have a process for this? Should we not delete questions which are the targets of closed-as-duplicate-of links? Should we unclose questions which have dangling closed-as-duplicate-of links? Should we delete them too?