Critical Description
A long running test I performed yesterday failed with a FileNotFoundException in the lucene index. After analyzing the issue it turned out the async index update persisted a conflict markers introduced by a rebase call. So far I'm not able to reproduce it with a more simple test setup and after a shorter time (the initial test failed after 10 hours). Given the way the async index update work, there shouldn't be any conflicts, because it's the only component writing into this location of the repository.
As an immediate workaround, I'd like to add the AnnotatingConflictHandler & ConflictValidator combo to the merge call to make sure a commit with conflict markers does not get persisted.