Fast-forward main from a feature branch without switching checkouts

When the working tree holds other people's uncommitted changes, you can still move main forward: check git merge-base --is-ancestor origin/main HEAD, then git push origin HEAD:main (plain push, so git refuses anything that isn't a fast-forward) and git fetch origin main:main to bring the local main ref along without checking it out. Commit with git commit -- <paths> so files someone else staged (for example deletions a logging hook staged) don't slip into your commit. Also confirm with the user which branch they expect to work on: a user who never asked for a feature branch may just want everything on main, in which case switch to main (free when both point at the same commit) and keep committing there.