How to undo a merge in GitHub

Question

I have been working in PhpStorm on a dedicated branch, but when pushing to github, I inadvertently merged to the master branch.

How would I undo the merge both in github and locally? The github master is used to migrate code to various servers so I need to rollback to the previous commit prior to the merge rather than create a new commit with my changes undone.

Possible duplicate of [Rollback a Git merge](http://stackoverflow.com/questions/11722533/rollback-a-git-merge) — Hatted Rooster, Mar 17 '17 at 14:35

kkflf · Accepted Answer · 2022-01-30T15:53:15.087

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You need to reset the head to the commit just before your current head.

git reset --hard <commit_before_merge>

E.g. git reset --hard master^

edited Jan 30 '22 at 15:53

answered Mar 17 '17 at 14:42

kkflf

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That will reset my local branch. Is it then just a case of pushing to update github? – Typhoon101 Mar 17 '17 at 14:51
You can either reset or checkout the previous commit and push that to github as head. Checkout the previous commit `checkout master^` – kkflf Mar 18 '17 at 18:42
But hard reset or previous commit will need force push, right? A force push overwrites public history and requires everyone who has cloned the repo to rebase their clone. – Siddu Oct 09 '19 at 15:50
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@Siddu Sorry for getting back to you so late. Yes, you have to do a force push. `git push -f`. – kkflf Dec 16 '19 at 20:48

score 9 · Answer 2 · answered Nov 09 '21 at 17:55

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To answer this more succinctly:

git checkout master
git reset --hard <commit_before_merge>
git push -f

answered Nov 09 '21 at 17:55

John Doherty

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How to undo a merge in GitHub

2 Answers2