Table of contents

• Understanding git revert
• How to revert a commit in git after already pushing the commit
• Alternative methods
• Best Practices
• Frequently asked questions

Sometimes, after pushing changes, you may need to undo these changes due to errors, or other unintended consequences. This guide will explore how to effectively revert a commit after it has been pushed to a remote repository, covering several methods and best practices.

Understanding git revert

"Reverting" in Git refers to creating a new commit that undoes the changes made by previous commits. This is different from "deleting" or "removing" a commit from the repository's history which makes it look like the commit never existed in the first place. Reverting retains the context of the commit and why it was removed.

How to revert a commit in git after already pushing the commit

Here’s a step-by-step guide on how to revert a pushed commit without rewriting the project history.

Step 1: Identify the commit to revert

First, you need to identify the commit you want to revert. You can view the commit history by running:

git log --oneline

This command shows a simplified commit log. Find the commit hash of the commit you wish to revert (the unique alphanumeric identifier generated by the SHA-1 hashing algorithm), and copy it.

Step 2: Revert the commit

Once you have the commit hash, you can revert it using:

git revert <commit-hash>

This command creates a new commit that undoes the changes made by the commit specified by <commit-hash>. If the commit in question introduced changes across multiple files, Git might prompt you to confirm the revert process for each conflicted file.

Step 3: Resolve any conflicts

If the revert process introduces conflicts (because the changes in the commit being reverted interact with changes made in subsequent commits), Git will pause the operation and allow you to manually resolve these conflicts. Once you have resolved any conflicts:

1. Add the resolved files to the staging area using:
   Terminal

   git add <file-name>
   
   

2. Complete the revert process by running:
   Terminal

   git revert --continue
   
   

For a detailed guide on resolving merge conflicts, see this guide.

Step 4: Push the revert commit

After successfully reverting the commit locally, push the changes to the remote repository:

git push origin <branch-name>

This updates the remote branch with the new commit that effectively undoes the changes made by the previous commit.

Alternative methods

Reverting multiple commits

If you need to revert more than one commit, you can use the git revert to specify a range of commits:

git revert --no-commit <newest-commit-hash>^..<oldest-commit-hash>
git commit -m "Revert multiple commits"

This command sequence reverts all changes in the specified range, combining them into a single commit.

Best Practices

1. Communicate with your team: Before reverting commits that have been pushed, especially in shared repositories, inform your team about the changes.
2. Avoid rewriting public history: Prefer git revert over methods like git reset for public branches to avoid creating synchronization issues for others.

For further reading on reverting commits in Git see the official Git documentation.

Frequently asked questions

What's the difference between git revert and git reset?

git revert creates a new commit that undoes the changes from a previous commit, preserving the commit history. git reset moves the branch pointer to a previous commit, effectively removing commits from the history. Use git revert for commits that have already been pushed to shared repositories, and git reset only for local commits that haven't been shared.

Can I revert a merge commit?

Yes, you can revert a merge commit, but it requires special handling. Use the -m flag to specify which parent to revert to:

git revert -m 1 <merge-commit-hash>

The -m 1 tells Git to revert to the first parent (usually the main branch), while -m 2 would revert to the second parent (the branch that was merged).

What happens if I revert a commit that was already reverted?

If you try to revert a commit that was already reverted, Git will typically show an error or create an empty commit. You can force the revert with the --no-edit flag, but it's generally better to check the commit history first to avoid confusion.

How do I revert the most recent commit?

To revert the most recent commit, you can use:

git revert HEAD

This is equivalent to git revert <commit-hash> where <commit-hash> is the hash of the most recent commit.

Can I revert a revert?

Yes, you can revert a revert commit. This effectively reapplies the original changes. Simply use git revert on the revert commit hash:

git revert <revert-commit-hash>

What if I want to revert multiple commits in a specific order?

To revert multiple commits in reverse chronological order (newest first), you can revert them one by one:

git revert <newest-commit-hash>
git revert <second-newest-commit-hash>
# ... and so on

Alternatively, you can revert a range of commits in a single operation:

git revert --no-commit <newest-commit-hash>^..<oldest-commit-hash>
git commit -m "Revert multiple commits"

How do I check what a revert will do before executing it?

You can preview what a revert will do by using the --no-commit flag and then checking the changes:

git revert --no-commit <commit-hash>
git diff --cached

If you don't want to proceed, you can abort the revert with:

git revert --abort