git revert to undo a commit safely - Step-by-Step Execution

Process Flow - git revert to undo a commit safely

Identify commit to undo

↓

Run git revert <commit>

↓

Git creates a new commit

↓

New commit reverses changes

↓

Push changes to remote (optional)

This flow shows how git revert safely undoes a commit by creating a new commit that reverses the changes.

Execution Sample

Git

git revert abc1234
# Creates a new commit that undoes abc1234

This command safely undoes the changes introduced by commit abc1234 by making a new commit that reverses them.

Process Table

Step	Action	Git Response	Resulting State
1	Identify commit abc1234 to revert	Commit hash abc1234 found	Ready to revert commit
2	Run git revert abc1234	Preparing revert of abc1234	New revert commit created (pending)
3	Git opens editor for commit message	User confirms commit message	Revert commit finalized
4	Revert commit added to branch	Commit abc1234 reversed by new commit	Branch history updated with revert
5	Optional: git push	Push successful	Remote branch updated with revert commit

💡 Revert commit created and branch history safely updated without deleting original commit

Status Tracker

Variable	Start	After Step 2	After Step 4	Final
HEAD	points to commit before abc1234	still points to commit before abc1234	points to new revert commit	points to new revert commit
Branch history	includes abc1234	includes abc1234	includes abc1234 + revert commit	includes abc1234 + revert commit

Key Moments - 2 Insights

Why does git revert create a new commit instead of deleting the old one?

Git revert adds a new commit that reverses changes to keep history safe and avoid rewriting history, as shown in execution_table step 4.

What happens if you push after revert?

Pushing sends the new revert commit to the remote repository, updating it safely without removing any commits, as in execution_table step 5.

Visual Quiz - 3 Questions

Look at the execution table, what does git do at step 3?

A Deletes the original commit

B Pushes changes to remote

C Opens editor for revert commit message

D Checks out a new branch

💡 Hint

Check the 'Git Response' column at step 3 in the execution_table

At which step is the revert commit finalized?

A Step 3

B Step 1

C Step 5

D Step 2

💡 Hint

Look at the 'Resulting State' column for when the revert commit is finalized

If you skip pushing after revert, what happens to the remote branch?

A Remote branch gets revert commit automatically

B Remote branch stays unchanged

C Remote branch deletes the original commit

D Remote branch resets to previous commit

💡 Hint

Refer to step 5 in execution_table about pushing changes

Concept Snapshot

git revert <commit>
Creates a new commit that reverses the changes of the specified commit.
Does NOT delete or rewrite history.
Safe way to undo changes in shared branches.
Push the revert commit to update remote repository.

Full Transcript

Git revert safely undoes a commit by creating a new commit that reverses the changes. First, you identify the commit to undo. Then you run 'git revert <commit>'. Git prepares a new commit that reverses the changes and opens an editor for the commit message. After confirming, the revert commit is finalized and added to the branch history. Optionally, you push the new commit to update the remote repository. This method keeps the original commit intact, preserving history and avoiding conflicts.

Practice

1. What does the git revert command do in a Git repository?

easy

A. It merges two branches together.

B. It deletes the commit from the project history permanently.

C. It resets the branch to a previous commit without creating a new commit.

D. It creates a new commit that undoes the changes of a previous commit.

Solution

1. Step 1: Understand the purpose of git revert

   git revert creates a new commit that reverses the changes made by a specified previous commit.

2. Step 2: Compare with other commands

   Unlike git reset, it does not remove commits from history but safely adds a new commit to undo changes.

3. Final Answer:

   It creates a new commit that undoes the changes of a previous commit -> Option D

4. Quick Check:

   git revert = new commit undoing changes [OK]

Hint: Remember: revert adds a new commit to undo changes [OK]

Common Mistakes:

• Confusing revert with reset which removes commits
• Thinking revert deletes commits permanently
• Assuming revert merges branches

2. Which of the following is the correct syntax to revert the latest commit in Git?

easy

A. git revert HEAD

B. git revert --latest

C. git revert -m HEAD

D. git revert --undo HEAD

Solution

1. Step 1: Identify the correct command to revert the latest commit

   The latest commit is referenced by HEAD, and the correct command is git revert HEAD.

2. Step 2: Check invalid options

   Options like --latest, -m without context, or --undo are not valid revert flags.

3. Final Answer:

   git revert HEAD -> Option A

4. Quick Check:

   Revert latest commit = git revert HEAD [OK]

Hint: Use HEAD to revert the latest commit safely [OK]

Common Mistakes:

• Using invalid flags like --latest or --undo
• Confusing revert options with reset options
• Trying to revert without specifying a commit

3. Given the following Git commands executed in order:

git commit -m "Add feature A"
git commit -m "Fix bug B"
git revert HEAD

What will be the result of the last command?

medium

A. The commit "Fix bug B" is deleted from history.

B. The branch is reset to the commit "Add feature A" without a new commit.

C. A new commit is created that undoes the changes from "Fix bug B".

D. An error occurs because HEAD cannot be reverted.

Solution

1. Step 1: Identify the commit pointed by HEAD

   After two commits, HEAD points to "Fix bug B" commit.

2. Step 2: Understand what git revert HEAD does

   It creates a new commit that reverses the changes introduced by the latest commit "Fix bug B".

3. Final Answer:

   A new commit is created that undoes the changes from "Fix bug B" -> Option C

4. Quick Check:

   git revert HEAD = new commit undoing latest commit [OK]

Hint: Revert HEAD always creates a new undo commit [OK]

Common Mistakes:

• Thinking revert deletes commits from history
• Confusing revert with reset which moves HEAD
• Assuming revert causes errors on HEAD

4. You ran git revert abc123 but got a merge conflict error. What should you do to fix this?

medium

A. Run git revert --abort to cancel the revert and try again.

B. Manually resolve the conflicts, then run git revert --continue.

C. Delete the commit abc123 and try reverting again.

D. Use git reset --hard to fix the conflict.

Solution

1. Step 1: Understand merge conflicts during revert

   Revert can cause conflicts if changes overlap. You must resolve conflicts manually.

2. Step 2: Continue revert after resolving conflicts

   After fixing conflicts, run git revert --continue to complete the revert commit.

3. Final Answer:

   Manually resolve the conflicts, then run git revert --continue -> Option B

4. Quick Check:

   Resolve conflicts + git revert --continue = fix revert conflict [OK]

Hint: Fix conflicts, then run git revert --continue [OK]

Common Mistakes:

• Trying to delete commits to fix revert conflicts
• Using git reset which discards changes unsafely
• Aborting revert without resolving conflicts

5. You want to undo a commit that was pushed and shared with your team, but keep the project history intact. Which approach is safest?

hard

A. Use git revert <commit-hash> to create a new commit that undoes the changes.

B. Use git reset --hard <commit-hash> and force push to rewrite history.

C. Delete the commit from the remote repository manually.

D. Use git checkout <commit-hash> to switch to the previous commit.

Solution

1. Step 1: Consider shared repository safety

   When commits are shared, rewriting history (reset + force push) can cause problems for others.

2. Step 2: Use revert to safely undo changes

   git revert adds a new commit that reverses changes without rewriting history, keeping the project safe and intact.

3. Final Answer:

   Use git revert <commit-hash> to create a new commit that undoes the changes -> Option A

4. Quick Check:

   Revert = safe undo for shared commits [OK]

Hint: Revert to undo shared commits safely, never reset [OK]

Common Mistakes:

• Using reset and force push on shared branches
• Deleting commits manually from remote
• Checking out old commits without reverting