Editing commit messages with rebase in Git - Cheat Sheet & Quick Revision

Recall & Review

beginner

What command starts an interactive rebase to edit commit messages?

Use git rebase -i HEAD~n where n is the number of commits you want to edit.

beginner

In an interactive rebase, how do you mark a commit to edit its message?

Change the word pick to reword next to the commit you want to edit.

beginner

What happens after you save and close the rebase todo list with reword commits?

Git opens an editor for each reword commit so you can change its message.

beginner

How do you finish the rebase after editing commit messages?

Save and close the commit message editor for each commit, then Git completes the rebase automatically.

intermediate

Why should you be careful when rebasing commits that are already shared with others?

Because rebasing rewrites history, it can cause problems for others who have the old commits.

Which command lets you edit the last 3 commit messages?

A git commit --amend

B git rebase -i HEAD~3

C git log -3

D git reset --soft HEAD~3

The command git rebase -i HEAD~3 opens an interactive rebase for the last 3 commits.

In the rebase todo list, which word should you replace pick with to change a commit message?

A reword

B fixup

C edit

D squash

Use reword to tell Git you want to change the commit message.

What does Git do after you save the rebase todo list with reword commits?

A Opens an editor for each commit message to be changed

B Deletes the commits

C Automatically merges commits

D Pushes changes to remote

Git opens the editor for each reword commit so you can edit the message.

What should you do after editing all commit messages during a rebase?

A Run git push --force

B Run git commit --amend

C Run git merge

D Save and close the editor to let Git finish the rebase

After editing messages, saving and closing the editor lets Git complete the rebase.

Why is it risky to rebase commits that others have already pulled?

A It deletes the remote repository

B It slows down Git performance

C It rewrites history, causing conflicts for others

D It automatically merges unrelated branches

Rebasing rewrites commit history, which can cause problems for collaborators who have the old commits.

Explain the steps to edit commit messages using interactive rebase.

Think about how you tell Git which commits to change and how you update messages.

Why should you avoid rebasing commits that have been pushed to a shared repository?

Consider what happens when history changes after sharing.

Practice

1. What does the command git rebase -i HEAD~3 allow you to do?

easy

A. Delete the last 3 commits permanently

B. View the commit history without changes

C. Create 3 new commits automatically

D. Interactively edit the last 3 commits, including their messages

Solution

1. Step 1: Understand the command purpose

   git rebase -i HEAD~3 opens an interactive editor for the last 3 commits.

2. Step 2: Recognize the interactive editing feature

   It allows changing commit messages, reordering, or squashing commits.

3. Final Answer:

   Interactively edit the last 3 commits, including their messages -> Option D

4. Quick Check:

   Interactive rebase edits commits [OK]

Hint: Use -i with HEAD~N to edit last N commits [OK]

Common Mistakes:

• Thinking it deletes commits
• Assuming it creates new commits
• Confusing it with git log

2. Which line correctly changes a commit action to edit its message during an interactive rebase?

easy

A. reword abc123 Update README with new info

B. pick abc123 Fix typo in README

C. edit abc123 Add new feature

D. delete abc123 Remove unused file

Solution

1. Step 1: Identify the correct keyword for editing messages

   In interactive rebase, reword lets you change the commit message only.

2. Step 2: Compare options

   edit pauses for full commit changes, pick keeps commit as is, delete is invalid here.

3. Final Answer:

   reword abc123 Update README with new info -> Option A

4. Quick Check:

   Use 'reword' to edit message only [OK]

Hint: Change 'pick' to 'reword' to edit commit messages [OK]

Common Mistakes:

• Using 'edit' when only message change is needed
• Leaving 'pick' unchanged
• Using invalid 'delete' keyword

3. After running git rebase -i HEAD~2 and changing the first commit's action from pick to reword, what happens next?

medium

A. Git deletes the first commit

B. Git opens an editor to change the first commit message, then continues rebase

C. Git aborts the rebase immediately

D. Git merges the two commits automatically

Solution

1. Step 1: Understand 'reword' effect during rebase

   Changing 'pick' to 'reword' tells Git to pause and open the commit message editor for that commit.

2. Step 2: Follow rebase process

   After editing the message, Git continues applying remaining commits automatically.

3. Final Answer:

   Git opens an editor to change the first commit message, then continues rebase -> Option B

4. Quick Check:

   'reword' opens message editor [OK]

Hint: Reword pauses to edit message, then continues [OK]

Common Mistakes:

• Thinking rebase aborts on reword
• Assuming commits get deleted
• Expecting automatic merge without editing

4. You ran git rebase -i HEAD~2 and changed 'pick' to 'reword' for the second commit, but after saving, Git shows an error: error: could not apply abc123. What is the likely cause?

medium

A. You used 'reword' instead of 'edit'

B. You forgot to save the commit message editor

C. There is a conflict applying the second commit during rebase

D. The commit hash is invalid

Solution

1. Step 1: Understand the error message

   error: could not apply abc123 means Git failed to apply that commit, usually due to conflicts.

2. Step 2: Relate to rebase process

   During rebase, conflicts can happen if changes overlap; you must resolve them manually.

3. Final Answer:

   There is a conflict applying the second commit during rebase -> Option C

4. Quick Check:

   Apply error = conflict during rebase [OK]

Hint: Apply errors usually mean conflicts to resolve [OK]

Common Mistakes:

• Assuming 'reword' causes error by itself
• Ignoring conflict resolution step
• Thinking commit hash is wrong

5. You want to edit the commit messages of the last 4 commits but keep the commit content unchanged. Which sequence of commands and actions is correct?

hard

A. Run git rebase -i HEAD~4, change all 'pick' to 'reword', save, then edit each message when prompted

B. Run git commit --amend four times in a row

C. Run git reset --soft HEAD~4 and recommit with new messages

D. Run git rebase -i HEAD~4, change 'pick' to 'edit', then change messages and contents

Solution

1. Step 1: Choose the right rebase command

   git rebase -i HEAD~4 opens interactive rebase for last 4 commits.

2. Step 2: Use 'reword' to edit messages only

   Changing 'pick' to 'reword' lets you edit commit messages without changing content.

3. Step 3: Save and edit messages when prompted

   Git opens editor for each commit message in turn; you update and save them.

4. Final Answer:

   Run git rebase -i HEAD~4, change all 'pick' to 'reword', save, then edit each message when prompted -> Option A

5. Quick Check:

   Use 'reword' in interactive rebase for message edits only [OK]

Hint: Use 'reword' for messages, 'edit' for content changes [OK]

Common Mistakes:

• Using commit --amend repeatedly instead of rebase
• Resetting and recommitting loses history
• Using 'edit' when only message change needed