Rollback a Git merge – Dev

The best answers to the question “Rollback a Git merge” in the category Dev.

QUESTION:

develop branch
--> dashboard (working branch)

I use git merge --no-ff develop to merge any upstream changes into dashboard

git log:

commit 88113a64a21bf8a51409ee2a1321442fd08db705
Merge: 981bc20 888a557
Author: XXXX <>
Date:   Mon Jul 30 08:16:46 2012 -0500

    Merge branch 'develop' into dashboard

commit 888a5572428a372f15a52106b8d74ff910493f01
Author: root <[email protected]>
Date:   Sun Jul 29 10:49:21 2012 -0500

    fixed end date edit display to have leading 0

commit 167ad941726c876349bfa445873bdcd475eb8cd8
Author: XXXX <>
Date:   Sun Jul 29 09:13:24 2012 -0500

The merge had about 50+ commits in it, and I am wondering how to just revert the merge so dashboard goes back to the state pre-merge

The second part of this is, if I dont do merge with --no-ff, I don’t get the commit ‘Merge branch ‘develop’ into dashboard‘ .. How would I roll that merge back?

ANSWER:

From here:

http://www.christianengvall.se/undo-pushed-merge-git/

git revert -m 1 <merge commit hash>

Git revert adds a new commit that rolls back the specified commit.

Using -m 1 tells git that this is a merge and we want to roll back to the parent commit on the master branch. You would use -m 2 to specify the develop branch.

ANSWER:

Reverting a merge commit has been exhaustively covered in other questions. When you do a fast-forward merge, the second one you describe, you can use git reset to get back to the previous state:

git reset --hard <commit_before_merge>

You can find the <commit_before_merge> with git reflog, git log, or, if you’re feeling the moxy (and haven’t done anything else): git reset --hard [email protected]{1}

ANSWER:

git revert -m 1 88113a64a21bf8a51409ee2a1321442fd08db705

But may have unexpected side-effects. See --mainline parent-number option in git-scm.com/docs/git-revert

Perhaps a brute but effective way would be to check out the left parent of that commit, make a copy of all the files, checkout HEAD again, and replace all the contents with the old files. Then git will tell you what is being rolled back and you create your own revert commit 🙂 !

ANSWER:

Just reset the merge commit with git reset --hard HEAD^.

If you use –no-ff git always creates a merge, even if you did not commit anything in between. Without –no-ff git will just do a fast forward, meaning your branches HEAD will be set to HEAD of the merged branch. To resolve this find the commit-id you want to revert to and git reset --hard $COMMITID.