This chapter, along with Chapter 6, Advanced Branching Techniques, provided all the tools required to manage a clean, readable, and easy-to-review history of a project.

You have learned how to make history more clean by rewriting it, and what does rewriting history mean in Git, when and why to avoid it, and how to recover from an untimely upstream rewrite. You have learned to use an interactive rebase to delete, reorder, squash, and split commits, and how to test each commit during rebase. You know how to do large-scale scripted rewrite with filter-branch: how to edit commits and commit metadata and how to permanently change history, for example, splitting it in two. You also got to know some third-party external tools, which can help with these tasks.

You learned what to do if you cannot rewrite history: how to fix mistakes by creating commits with appropriate changes (for example with git revert), how to add extra information to the existing commits with notes, and how to change the virtual view of the history with replacements. You learned to handle reverting a faulty merge and re-merging after reverted merge. You know how to fetch and publish both notes and replacements.

To really understand advanced history rewriting and the mechanism behind notes and replacements, this chapter explained the basics of Git internals and low-level commands usable for scripting (including scripted rewrite).

The following chapter, Chapter 9, Managing Subprojects - Building a Living Framework, will explain and show different ways to connect different subprojects in one repository, from submodules to subtrees.

You will also learn techniques to manage or mitigate managing large-size assets inside a repository. Splitting a large project into submodules is one, but not the only way to handle this issue.