Git: How To Revert A Branch Merge

This was a stumper for me a while back. Jason Meridth posted on reseting / reverting git commits and I had a question in the comments. My specific situation was about having a branch merged at the wrong time and how to undo that merge. Here’s an example of the situation, shown with gitk:


In this scenario, the “test” branch was not supposed to be merged yet… i missed some changed, or i needed to do something else with the master branch, etc. Whatever the reason, I wanted to rollback to the point where test and master were not yet merged. As i stated in the comments on jason’s post, I ran around in circles trying to get ‘git revert’ to do what I wanted, with no luck. Lucky for me, Nick Quranto had a blog post on reverting with git, pointed me toward an in-depth read on the subject and was happy to answer my questions via email.

It turned out the answer was much more simple than what I was trying to do. Since I merged the test branch into the master branch, I can run this from the master branch:

   1: git reset --hard HEAD^

Here, you can see that this moves the HEAD of master back to the previous commit (Note: for more info on what HEAD^ means, see Git Treeishes in the git docs):


Apparently the “revert” command differs from the “reset” command in a very important way: revert will take the changes from whatever commit you specify and undo them, creating a new commit for the new version. In contrast to that, “reset” will move the pointer that represents your branch’s location to whatever point you specify. So, doing a reset on the test master branch allowed me to move the current location of HEAD back to the previous commit on that branch (Another Note: I know I’m messing up the detail on how reset vs. revert works… this is just a basic high level experience report, rather than an in-depth discussion on what really goes on).

The result looks like this in gitk:


This is exactly what I wanted: the master and test branch are no longer merged and I can continue working on either / both of them independently with the ability to merge them together at some later point in time.

Post Footer automatically generated by Add Post Footer Plugin for wordpress.

About Derick Bailey

Derick Bailey is an entrepreneur, problem solver (and creator? :P ), software developer, screecaster, writer, blogger, speaker and technology leader in central Texas (north of Austin). He runs - the amazingly awesome podcast audio hosting service that everyone should be using, and where he throws down the JavaScript gauntlets to get you up to speed. He has been a professional software developer since the late 90's, and has been writing code since the late 80's. Find me on twitter: @derickbailey, @mutedsolutions, @backbonejsclass Find me on the web: SignalLeaf, WatchMeCode, Kendo UI blog, MarionetteJS, My Github profile, On Google+.
This entry was posted in Branching Strategies, Git, Source Control. Bookmark the permalink. Follow any comments here with the RSS feed for this post.
  • Nick Quaranto

    Ahh, glad you got it figured out. git reset –head HEAD^ works great if you haven’t pushed the merge out. Otherwise you’re stuck with reverting it or looking into that lengthy post from Linus. :)

  • James Dunlop

    Hi Derick,
    Just to let you know your link to the article by Linus Torvalds should be changed to:

  • Salsan Jose

    How to detach all of the merges of a particular branch in one try?