I recently came across a duplicate question. However, the question it a a duplicate of is deleted. What is the right thing to do in this case? Should I flag the the duplicate for unduplication? Should I just leave it alone?
I undeleted the original, which had been deleted by an automatic process, but then realized that it had been closed as a gen ref question. So I redeleted it and reopened the other instead (un-duplicated it).
It is a good idea to flag these with a custom flag and tell us that the linked duplicate has been deleted. This kind of thing happens sometimes, where an auto-delete occurs, and we don't know that it has been linked to something. We're not likely to notice unless someone flags it.
It is a good idea to flag posts that have dead links as well, again with a custom flag that mentions that the link is dead. This is sort of a special case of that.
Thanks for asking, and thanks for helping.