Merging work back

New idea

Bring the feature home

Your feature is done on its branch. Now main needs it. You switch to main and run git merge feature. What Git does depends on one question: has `main` moved since you branched off?

If it hasn't, main's commit is an ancestor of feature's tip (you can reach it by following parent arrows back from feature's tip). In other words, feature already contains everything main has, plus more. Nothing needs combining, so Git slides the main label forward to feature's commit.

This is a fast-forward. No new commit is made. A label moves, and that's all.