Undo the new merge request in Gitlab

2 min read 06-10-2024

How to Undo a Merge Request in GitLab: A Step-by-Step Guide

Scenario: You've just merged a new feature branch into your main branch in GitLab, but you realize you've made a mistake. Maybe you forgot to test something crucial, or the code isn't working as intended. Now you need to undo that merge request and fix the problem.

Problem: How can you effectively revert a merge request in GitLab without causing further issues?

Solution: Fortunately, GitLab provides several ways to undo a merge request, depending on your specific needs. This article will guide you through the most common methods, ensuring a smooth recovery from your merge mistake.

Understanding the Process

Before we dive into the solutions, it's important to understand that GitLab offers two primary approaches for undoing a merge request:

Reverting: This creates a new commit that undoes the changes introduced by the original merge. This is a good option if you want to keep the original merge history intact.
Resetting: This changes the branch's history by rewriting it, effectively removing the merged commit. Use this approach cautiously, as it can be more complex and require a deeper understanding of Git.

Reverting a Merge Request

This is the recommended approach for most scenarios. Here's how to revert a merge request:

Identify the Merge Commit: Navigate to the main branch (usually main or master) and find the commit ID of the merge you want to revert. It should be labelled as Merge branch 'your-feature-branch' into main.
Create a Revert Commit: Open your terminal and navigate to your Git repository. Run the following command:
```
git revert <merge_commit_id>
```
Replace <merge_commit_id> with the actual ID of the merge commit. You'll be prompted to write a commit message explaining the revert.
Push the Changes: Push your changes to the remote repository:
```
git push origin main 
```

Now, you'll have a new commit that undoes the merge. Your main branch will be restored to the state before the problematic merge.

Resetting a Merge Request

This option is more advanced and might not be suitable for everyone. It permanently removes the merged commit from the branch history. Use this method with caution if you're sure you don't need the merged commit.

Hard Reset to Before the Merge: Find the commit ID of the commit before the merge. You can navigate the commit history in GitLab's interface to identify this commit. Then, use the following command in your terminal:
```
git reset --hard <previous_commit_id>
```
Force Push: Push your changes to the remote repository, but use the --force flag to overwrite the existing history:
```
git push --force origin main
```

Warning: This will completely overwrite the remote branch's history. Ensure there are no other users working on the branch before using the --force command.

Additional Tips

GitLab Interface: GitLab provides a user-friendly interface to manage your merge requests. You can find options to revert or reset your branch within the merge request details page.
Collaboration: If you're working in a team, communicate your plan to revert the merge request to avoid conflicts.
Backup: Before reverting or resetting, create a backup of your repository to ensure you have a safe copy of your code.

Conclusion

Mistakes happen, and GitLab provides you with the tools to recover from them effectively. By understanding the differences between reverting and resetting, you can confidently choose the best method to undo a merge request. Remember to be cautious and communicate your actions to your team to ensure a smooth workflow.