Automattic/Co-Authors-Plus — pull request #220 by nickdaugherty (2014-09-05 18:42:43+00:00)
Title: Clear Guest Author caches upon Guest Author creation

After a Guest Author is created, we should flush all caches to ensure
any previously cached negative results are gone.

Also need to `$force` the lookup in `delete_guest_author_cache()` to
ensure it never hits a stale negative cache entry.

Fixes #218