PullRequestService.merge does not check whether the pull request is open before attempting to merge it. As a result, when merge is called with a pull request that is already merged, git reports "Already up-to-date."

This is interpreted as an error and the pull request is put back in the OPEN state (because the merge failed). The next time pull request rescoping is triggered in the repository, the pull request is marked as "merged remotely" again.