gitundogit-merge

Undo a Git merge that hasn't been pushed yet


I accidentally ran git merge some_other_branch on my local master branch. I haven't pushed the changes to origin master. How do I undo the merge?


After merging, git status says:

# On branch master
# Your branch is ahead of 'origin/master' by 5 commits.

How do I undo all these commits?


Solution

  • With git reflog check which commit is one prior the merge (git reflog will be a better option than git log). Then you can reset it using:

    git reset --hard commit_sha
    

    There's also another way:

    git reset --hard HEAD~1
    

    It will get you back 1 commit.

    Be aware that any modified and uncommitted/unstashed files will be reset to their unmodified state. To keep them either stash changes away or see --merge option below.


    As @Velmont suggested below in his answer, in this direct case using:

    git reset --hard ORIG_HEAD
    

    might yield better results, as it should preserve your changes. ORIG_HEAD will point to a commit directly before merge has occurred, so you don't have to hunt for it yourself.


    A further tip is to use the --merge switch instead of --hard since it doesn't reset files unnecessarily:

    git reset --merge ORIG_HEAD
    

    --merge

    Resets the index and updates the files in the working tree that are different between <commit> and HEAD, but keeps those which are different between the index and working tree (i.e. which have changes which have not been added).