How to Undo a Commit in Git and Remove It From the Log

In Git, ‘undoing’ refers to various operations that correct or revert changes made to a project’s history or local files. This process involves different methods, each suited for specific scenarios where modifications need to be reversed. The choice of method depends on whether the changes are local, already committed, or have been shared with others.

Modifying the Most Recent Commit

When a small correction is needed immediately after a commit, such as a typo in the commit message or a forgotten file, the `git commit –amend` command modifies the most recent commit by combining newly staged changes with the previous commit. It can also be used simply to edit the last commit message if no other changes are staged.

Another method for addressing a recently made commit is `git reset –soft HEAD~1`. This command moves the current branch’s pointer back one commit. It preserves all the changes from that undone commit in your staging area, ready to be re-committed with new modifications or a different message. Both `git commit –amend` and `git reset –soft HEAD~1` are safe when the commit has not yet been pushed to a remote repository. Amending or resetting pushed commits can lead to complexities for collaborators, as it rewrites history.

Undoing a Published Commit

When a commit has already been pushed to a shared (remote) repository, or if you need to undo an earlier commit in the history, `git revert ` is the preferred command. Unlike other undo operations that rewrite history, `git revert` creates a new commit that precisely undoes the changes introduced by a specified previous commit. This means the project’s history remains intact.

The advantage of `git revert` is its non-destructive nature, which makes it ideal for collaborative environments. Since it adds a new commit to reverse the effects of an old one, rather than removing the old commit, it avoids conflicts for other team members who may have already pulled the original commit. To use it, you identify the unique hash (ID) of the commit you wish to undo, then execute `git revert` followed by that hash. Git will then generate a new commit that applies the inverse of the changes from the specified commit, effectively canceling them out in the project’s timeline.

Removing Commits from History

For more drastic “undo” operations that rewrite history, particularly on local, unpushed branches, the `git reset` command offers powerful options. `git reset –hard ` is highly destructive. This command moves the current branch pointer to the specified commit and simultaneously discards all subsequent commits and any local changes in both the staging area and the working directory. It effectively reverts your repository to the exact state of the target commit, permanently losing any work that came after it.

A less severe but still history-rewriting option is `git reset –mixed `, which is also the default behavior if no flag is specified with `git reset`. This command discards commits by moving the branch pointer, but it keeps the changes from those discarded commits in your working directory as unstaged modifications. This allows you to re-evaluate and selectively re-stage or discard those changes. While both `–hard` and `–mixed` alter commit history, `–hard` should be used with extreme caution due to its potential for irreversible data loss, ideally only on private branches where no one else depends on the history.

Restoring Files or Discarding Local Changes

Sometimes, the need to “undo” is not about commit history but about managing uncommitted changes in your local working directory or staging area. The `git restore ` command provides a focused way to discard changes within a specific file in your working directory. This reverts the file to its state from the last commit or the staging area.

If changes have been added to the staging area but not yet committed, `git restore –staged ` can be used to unstage them. This moves the changes back to the working directory, allowing you to modify them further or decide not to include them in the next commit. For discarding untracked files and directories, `git clean -fd` can be employed. These commands are useful for managing immediate, local modifications and do not impact the project’s commit history.