How to revert to a previous commit in Git

Reverting changes to a previous commit in Git is useful when you need to undo changes that have been made since the time of a certain commit. This might be necessary for removing introduced bugs, undoing a feature, or simply resetting the project to a stable state. This guide covers how to revert to previous commits in Git, including entire commits or specific files, using commands like git revert to previous commit and more.

Understanding Git revert

The git revert command generates a new commit that undoes the changes made in one or more existing commits. This is a safe way to undo changes, as it doesn't alter the project's commit history. Instead, it adds a new commit on top that reverses the effect of earlier commits.

Why you might need to revert to a previous commit

Here are some reasons you might find yourself needing to revert to a previous commit:

• Bug introduction: If a recent commit introduces errors or bugs, reverting can restore the last known good state.
• Feature rollback: Rolling back features that are no longer needed or that were added prematurely.
• Merge mistakes: Correcting issues caused by incorrect merges.

How to revert to a previous commit in Git

Step 1: Identify the commit

First, identify the commit to which you want to revert. You can view the commit history using:

git log

This command shows a list of recent commits, including their commit IDs, author, date, and the commit message. Find the commit ID of the commit just before the point you want to revert to.

Step 2: Revert the entire commit

To revert the entire repository to the state of a previous commit, use:

git revert --no-commit <commit-id>..HEAD
git commit

Replace <commit-id> with the ID of the commit you're reverting to. This sequence of commands reverts all changes from the current HEAD back to the specified commit.

Step 3: Revert specific files

If you only need to revert changes to specific files, you can do so by checking out those files from a specific commit:

git checkout <commit-id> -- path/to/file

This command will bring the specified files back to their state at <commit-id>.

Step 4: Revert a range of commits

To revert a range of commits, you can use:

git revert --no-commit <commit-id>^..HEAD
git commit

This command reverts all changes made from the commit just before <commit-id> to the current HEAD.

Step 5: Push your changes

After reverting locally, you'll likely need to push your changes to the remote repository:

git push origin main

This updates the remote repository with your revert commits.

Common issues and troubleshooting

• Merge conflicts: Reverting changes can lead to merge conflicts, especially if subsequent changes have been made to the same parts of files. Resolve these conflicts as you would during a merge.
• Reverting a revert: If you need to undo a revert, you can use git revert again on the revert commit itself.

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