Golden rule of rebasing (never rebase public) in Git - Deep Dive

Overview - Golden rule of rebasing (never rebase public)

What is it?

The golden rule of rebasing in Git is to never rebase commits that have been shared publicly. Rebasing means rewriting the history of your commits to create a cleaner, linear sequence. However, if others have already based their work on those commits, changing them can cause confusion and conflicts.

Why it matters

This rule exists to prevent chaos in collaborative projects. Without it, rewriting shared history would force everyone else to fix their work, wasting time and causing errors. It keeps teamwork smooth and avoids breaking the shared codebase.

Where it fits

Before learning this, you should understand basic Git concepts like commits, branches, and pushing to remote repositories. After this, you can explore advanced Git workflows, conflict resolution, and collaborative branching strategies.

Mental Model

Core Idea

Never rewrite history that others depend on, because it breaks their work and causes confusion.

Think of it like...

It's like editing a shared group document after everyone else has started writing based on the original version; changing the past text forces everyone to redo their parts.

┌───────────────┐       ┌───────────────┐
│ Local Branch  │──────▶│ Rebase Commits│
└──────┬────────┘       └──────┬────────┘
       │                      │
       │                      ▼
       │               ┌───────────────┐
       │               │ Rewritten     │
       │               │ History       │
       │               └──────┬────────┘
       │                      │
       ▼                      ▼
┌───────────────┐       ┌───────────────┐
│ Public Branch │◀──────│ Shared Commits│
└───────────────┘       └───────────────┘

If you rebase commits already pushed to the public branch, others who pulled those commits face conflicts.

Build-Up - 6 Steps

1

Foundation

Understanding Git Commits and History

Concept: Learn what commits are and how Git tracks changes as a history.

A commit in Git is like a snapshot of your project at a point in time. Git stores these commits in a chain, called history, showing how your project evolved. Each commit has a unique ID and points to its parent commit, forming a timeline.

Result

You understand that commits form a chain representing your project's changes over time.

Understanding commits as snapshots helps you see why changing them later can affect the whole project history.

2

Foundation

What is Rebasing in Git?

Concept: Rebasing rewrites commit history to create a clean, linear sequence of changes.

Rebasing takes your commits and moves them to a new base commit, replaying them one by one. This removes unnecessary merge commits and makes history easier to read. It changes commit IDs because it creates new commits.

Result

You can perform a rebase to reorder or clean up your commits locally.

Knowing that rebasing creates new commits with new IDs explains why it changes history.

3

Intermediate

Difference Between Local and Public Commits

Concept: Distinguish commits only on your machine from those shared with others.

Local commits exist only on your computer until you push them to a shared repository. Public commits are those pushed and visible to others. Once public, others may base their work on these commits.

Result

You can identify which commits are safe to rebase and which are not.

Recognizing the boundary between local and public commits is key to safe rebasing.

4

Intermediate

Why Rebasing Public Commits Causes Problems

🤔Before reading on: do you think rebasing public commits only affects your work or also others'? Commit to your answer.

Concept: Rebasing public commits rewrites history others rely on, causing conflicts and confusion.

When you rebase commits already pushed, their IDs change. Others who pulled the old commits now have a different history. They must manually fix conflicts or reset their work, which is time-consuming and error-prone.

Result

You understand that rebasing public commits disrupts collaboration and causes merge conflicts.

Knowing the impact on others explains why rebasing public commits is risky and discouraged.

5

Advanced

How to Safely Use Rebase Locally

🤔Before reading on: do you think you can rebase any branch safely if you coordinate with your team? Commit to your answer.

Concept: Rebase is safe on local or private branches not shared with others.

Use rebase to clean up your local commits before pushing. For example, squash small fix commits into one. Always rebase only branches you haven't pushed or shared. Communicate with your team if unsure.

Result

You can improve your commit history without breaking others' work.

Understanding safe rebase practices helps maintain clean history and smooth teamwork.

6

Expert

Handling Mistakes: Undoing a Public Rebase

🤔Before reading on: do you think you can easily fix a public rebase mistake without affecting others? Commit to your answer.

Concept: Undoing a public rebase requires careful coordination and often force pushes, which can disrupt teammates.

If you accidentally rebase public commits, you must notify your team immediately. Use git reflog to find the old commit history and restore it. Then force push the original history back. Everyone else must reset their local branches to avoid conflicts.

Result

You can recover from a public rebase mistake but it requires teamwork and caution.

Knowing how to undo public rebases prevents prolonged disruption and loss of work.

Under the Hood

Git stores commits as objects with unique SHA-1 hashes. Rebasing creates new commits with new hashes by replaying changes on a new base. When you rebase public commits, the commit hashes change, breaking the chain others rely on. Git tracks branches as pointers to commits, so rewriting history moves these pointers, confusing collaborators who have the old pointers.

Why designed this way?

Git was designed to allow flexible history rewriting for cleaner logs and easier merges. However, because commits are identified by hashes, changing history changes commit identities. The rule to never rebase public commits emerged to protect collaboration integrity, balancing flexibility with teamwork safety.

┌───────────────┐       ┌───────────────┐
│ Original Base │──────▶│ Commit A      │
└──────┬────────┘       └──────┬────────┘
       │                      │
       │                      ▼
       │               ┌───────────────┐
       │               │ Commit B      │
       │               └──────┬────────┘
       │                      │
       ▼                      ▼
┌───────────────┐       ┌───────────────┐
│ New Base      │──────▶│ Commit A'     │
└──────┬────────┘       └──────┬────────┘
       │                      │
       │                      ▼
       │               ┌───────────────┐
       │               │ Commit B'     │
       │               └───────────────┘

Rebase creates new commits A' and B' with new hashes on a new base.

Myth Busters - 4 Common Misconceptions

Quick: Do you think rebasing public commits is safe if you inform your team? Commit yes or no.

Common Belief: Rebasing public commits is okay as long as you tell your team beforehand.

Reality: Even with notice, rebasing public commits forces everyone to fix their local history, causing confusion and errors.

Why it matters: Assuming communication solves the problem leads to broken workflows and wasted time fixing conflicts.

Quick: Do you think rebasing is the same as merging? Commit yes or no.

Common Belief: Rebasing and merging both combine changes and are interchangeable.

Reality: Rebasing rewrites history creating new commits; merging preserves history and adds a merge commit.

Why it matters: Confusing these leads to improper use of Git commands and unexpected history changes.

Quick: Do you think you can rebase any branch safely if you haven't pushed it yet? Commit yes or no.

Common Belief: You can always rebase any branch safely if it is only local.

Reality: Branches tracking remote branches or shared with others locally can cause conflicts if rebased without coordination.

Why it matters: Ignoring this causes unexpected conflicts and lost work even before pushing.

Quick: Do you think force pushing after rebasing public commits is harmless? Commit yes or no.

Common Belief: Force pushing after rebasing public commits is a normal practice and causes no issues.

Reality: Force pushing rewrites history on the remote, breaking others' clones and requiring them to reset their branches.

Why it matters: Misusing force push disrupts team productivity and can cause lost commits.

Expert Zone

1

Rebasing is safe on feature branches that are strictly personal and never pushed, but risky on shared branches even if not public.

2

Some teams use protected branches on remotes to prevent force pushes, enforcing the golden rule automatically.

3

Interactive rebasing allows selective editing of commits, but must still respect the public/private boundary.

When NOT to use

Never rebase branches that have been pushed to shared repositories or used by others. Instead, use merge commits to integrate changes safely. For public branches, prefer 'git merge' to preserve history and avoid rewriting commits.

Production Patterns

In professional workflows, developers rebase local feature branches before merging to main branches to keep history clean. Protected branches prevent rebasing public commits. Teams use pull requests with merge commits or squash merges to integrate changes without rewriting shared history.

Connections

Version Control Systems

Builds-on

Understanding rebasing deepens knowledge of how version control tracks and manages changes over time.

Collaborative Writing

Similar pattern

Like rebasing public commits, editing a shared document's past after others have worked on it causes confusion and extra work.

Database Transactions

Opposite pattern

Unlike rebasing which rewrites history, database transactions aim to keep a consistent, unchangeable record of changes to avoid conflicts.

Common Pitfalls

#1 Rebasing commits already pushed to a shared remote branch.

Wrong approach:

git rebase main
git push origin feature-branch --force

Correct approach:

git merge main
git push origin feature-branch

Root cause:

Misunderstanding that rebasing changes commit history and breaks others' work.

#2 Force pushing without team coordination after rebasing public commits.

Wrong approach:

git push origin feature-branch --force

Correct approach:

Avoid force push on public branches; use merge or coordinate carefully before force pushing.

Root cause:

Ignoring the impact of rewriting shared history on collaborators.

#3 Rebasing a branch that tracks a remote branch without updating local references.

Wrong approach:

git checkout feature-branch
git rebase main

Correct approach:

git fetch origin
git checkout feature-branch
git rebase origin/main

Root cause:

Not syncing with remote before rebasing leads to conflicts and outdated history.

Key Takeaways

Rebasing rewrites commit history by creating new commits with new IDs.

Never rebase commits that have been pushed to a shared or public repository.

Rebasing is safe and useful on local or private branches before sharing.

Rebasing public commits breaks others' work and causes conflicts.

Use merges for integrating changes on public branches to preserve history.