This is the return value of the bookkeeping layer, org.jabref.logic.git.merge.execution.MergeBookkeeper indicating "whether we performed a fast-forward or created a new (merge or single-parent) commit." It does not participate in any content synthesis; the input file content must be the merge result already prepared before the GUI. If "the local is strictly behind the remote and the file content is exactly the same as the remote" → fast-forward, no new commit is created; Otherwise:

• BEHIND (local is an ancestor of remote): create a new single-parent commit (parent=remote) on top of remote;
• DIVERGED: create a new dual-parent merge commit (parents=[local, remote]).

  Notes

  Because the statuses UP_TO_DATE / AHEAD / CONFLICT / UNTRACKED are already filtered out before prepareMerge by GitStatusChecker, they will not enter finalizeMerge.