Reversing a Historical Development Restoring Git Push's Original Commit History

Recovering Your Git Commit History: A Step-by-Step Guide

After a month of work on a personal project, I discovered that my user.name and user.email were incorrectly configured. Even after making these changes, I observed that the wrong author name was still present in my earlier commits. I attempted a git rebase in an effort to update my contribution graph by modifying these commits.

However, this resulted in mistakenly changing the commit dates, creating the impression that all of the commits were made at once. Following such an inadvertent alteration, this article attempts to aid you in restoring your original commit history, ensuring that your efforts are properly recognized.

Understanding Restoration of Git History

The scripts offered are meant to rectify and restore Git's commit history, especially in cases where an inadvertent rebase has changed commit dates. In the first script, the commit hash is found before the rebase process by utilizing git reflog. This command shows a history of all repository modifications, including resets and rebases. Upon locating the relevant commit hash, the branch is reset to that commit using the git reset --hard command, thereby erasing all subsequent modifications. This is an important step since it restores the repository to its previous state prior to the incorrect rebase. The local modifications are then pushed to the remote repository using the git push --force command, overwriting the previous history with the reset branch.

The second script's objective is to change the commit author details without affecting the commit dates. Using the git filter-branch --env-filter command, environment variables such as author and committer details can be modified across all commits. Variables like WRONG_EMAIL, CORRECT_NAME, and CORRECT_EMAIL are used to identify incorrect information and explain the proper ones. The script then uses export GIT_COMMITTER_NAME and export GIT_COMMITTER_EMAIL to update the committer details, followed by export GIT_AUTHOR_NAME and export GIT_AUTHOR_EMAIL for the author details. Option --tag-name-filter cat ensures that tags are rebuilt with the specified filters. This script can be used to update the commit history with the correct author information while maintaining the original commit dates.

# Step 1: Identify the commit hash before the rebase
git reflog
# Look for the commit hash before the rebase operation
# Step 2: Reset the branch to the commit before the rebase
git reset --hard <commit_hash>
# Step 3: Verify the reset
git log
# Ensure the commit history is back to its original state
# Step 4: Force push the reset history to the remote repository
git push --force

# Step 1: Rewrite author information without altering commit dates
git filter-branch --env-filter '
WRONG_EMAIL="wrong@example.com"
CORRECT_NAME="Correct Name"
CORRECT_EMAIL="correct@example.com"
if [ "$GIT_COMMITTER_EMAIL" = "$WRONG_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$WRONG_EMAIL" ]
then
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi'
--tag-name-filter cat -- --branches --tags

Restoring History With Git Without Losing Data

The use of git cherry-pick is another factor to take into account while working with Git history restoration. You can apply the modifications made by previous commits to the current branch with this command. When you have to manually reconstruct a history that was unintentionally changed, it can be quite helpful. For instance, if a rebase or reset goes awry and you would like to add back individual changes, you can utilize git cherry-pick to do so. This technique keeps the history of your project intact by preserving the original commit dates and messages.

git reflog is an additional helpful command. It displays a history of all the modifications made to the branches' tips and other repository references, even those that are often hidden from view in the git log. This lets you locate commit hashes that may have been overwritten or lost during unfavorable resets or rebases. Using a combination of git reflog and git reset --hard, you can revert modifications by restoring your branch to a former state. Furthermore, it's crucial to occasionally take snapshots of the status of your repository using git tag. Tags come in handy because they let you annotate particular historical moments that can be undone in the event of serious problems.