pub async fn merge_ff_only(repo: &Path, branch: &str) -> Result<GitOut>Expand description
Fast-forward branch into the currently checked-out branch, refusing to
create a merge commit.
Only ever fast-forwards because the winner was already rebased onto the
tracked base tip before this runs (Runner::sync_to_base); at that point
--ff-only is indistinguishable from GitHub’s “rebase and merge” button.
If the base moved again in the meantime this fails rather than falling
back to a real rebase, the same way merge_no_ff fails rather than
resolving a conflict — landing is not the place to improvise.