When trying to merge two Git branches that have diverged a lot, it's a little difficult to make sense of what happened on both sides.
Enter git merge-base--a simple built-in utility to tell you where two branches diverged. It will tell you the commit where the two branches split off:
$ git merge-base develop master b8ac838cad3266f6a7e414181875831fd9b86ed5
This command will create a tag
_base that will point to where they both diverged.
git tag _base `git merge-base develop master`
You can then use
git log, or tig to inspect changes on either side:
# Inspect changes in Gemfile on each side tig _base...develop -- Gemfile tig _base...master -- Gemfile git diff _base...develop -- Gemfile git diff _base...master -- Gemfile
You can also use the
--independent flag which will show commits that can't be reached by any other. If it prints 2 commits, it means that there are changes on both sides.
$ git merge-base develop master --independent 46978182cc8d90439b862e772e99a3f71889901a 8501118e0d958115caff692abda0f29ad530db4f
If it only prints 1, it means only one side has changes.
$ git merge-base develop master --independent 8501118e0d958115caff692abda0f29ad530db4f