Undo a Git merge that hasn't been pushed yet

Question

Within my master branch, I did a git merge some-other-branch locally, but never pushed the changes to origin master. I didn\'t mean to merge, so I\'d like to un

Answer 1

With modern Git, you can:

git merge --abort

Older syntax:

git reset --merge

Old-school:

git reset --hard

But actually, it is worth noticing that git merge --abort is only equivalent to git reset --merge given that MERGE_HEAD is present. This can be read in the Git help for merge command.

git merge --abort is equivalent to git reset --merge when MERGE_HEAD is present.

After a failed merge, when there is no MERGE_HEAD, the failed merge can be undone with git reset --merge, but not necessarily with git merge --abort, so they are not only old and new syntax for the same thing.

Personally I find git reset --merge much more powerful and useful in everyday work, so that's the one I always use.

Answer 2

Got to this question also looking to revert to match origin (ie, NO commits ahead of origin). Researching further, found there's a reset command for exactly that:

git reset --hard @{u}

Note: @{u} is shorthand for origin/master. (And, of course, you need that remote repository for this to work.)

Answer 3

1. First, make sure that you've committed everything.

2. Then reset your repository to the previous working state:

   $ git reset f836e4c1fa51524658b9f026eb5efa24afaf3a36
   

   or using --hard (this will remove all local, not committed changes!):

   $ git reset f836e4c1fa51524658b9f026eb5efa24afaf3a36 --hard
   

   Use the hash which was there before your wrongly merged commit.

3. Check which commits you'd like to re-commit on the top of the previous correct version by:

   $ git log 4c3e23f529b581c3cbe95350e84e66e3cb05704f
   
   commit 4c3e23f529b581c3cbe95350e84e66e3cb05704f
   
   ...
   
   commit 16b373a96b0a353f7454b141f7aa6f548c979d0a
   
   ...
   

4. Apply your right commits on the top of the right version of your repository by:

   • By using cherry-pick (the changes introduced by some existing commits)

         git cherry-pick ec59ab844cf504e462f011c8cc7e5667ebb2e9c7
     

   • Or by cherry-picking the range of commits by:

     • First checking the right changes before merging them:

       git diff 5216b24822ea1c48069f648449997879bb49c070..4c3e23f529b581c3cbe95350e84e66e3cb05704f
       

     • First checking the right changes before merging them:

       git cherry-pick 5216b24822ea1c48069f648449997879bb49c070..4c3e23f529b581c3cbe95350e84e66e3cb05704f
       

       where this is the range of the correct commits which you've committed (excluding wrongly committed merge).

Answer 4

If your merge and the corresponding commits were not pushed yet, you can always switch to another branch, delete the original one and re-create it.

For example, I accidentally merged a develop branch into master and wanted to undo that. Using the following steps:

git checkout develop
git branch -D master
git branch -t master origin/master

Voila! Master is at the same stage as origin, and your mis-merged state is erased.

Answer 5

1. git stash

2. git branch -d the_local_branch

3. git checkout -t <name of remote>

4. git stash apply

This worked for me..!!

Answer 6

If you notice that you need to revert immediately after the merge and you haven't done anything else after the merge attempt, you can just issue this command: git reset --hard HEAD@{1}.

Essentially, your merge sha will be pointing to HEAD@{0} if nothing else was committed after the merge and so HEAD@{1} will be the previous point before the merge.