How to add a missing file to a commit?

Question

Consider I have A, B , C , D commits and push them on remote repo.

After committing D I find there is a file that should be in B commit.

How can I edit B commit and add the missing file?

Answer 1

This will work assuming that no one else has pulled the code from remote. If that has happened, your history is no longer yours and this is a bad idea.

1. Make sure your repo is clean.
2. git rebase -i A
3. In your editor, change the entry for B to edit.
4. Start the rebase by closing your editor. git will stop at B.
5. git add file (where file is the file you want to add).
6. git commit --amend. Fix the commit message and commit
7. git rebase --continue to get the rest of the late commits.
8. git push --force.

Answer 2

You can use squash which is an interactive rebase. You just have to keep in mind what is the result of a rebase. Anyone who have a copy of the branch will have to delete it and fetch it again since your history was updated.

Once you are done re-writing history you will have to delete the remote branch or push using the -f to force the push.

---

In order to do a git squash follow those steps:

// X is the number of commits you wish to squash
git rebase -i HEAD~X

Once you squash your commits - choose the e for editing the content of the desired commit, make your changes and commit it. In your case add the missing file to the B commit.

---

You also have the --root flag in case you need it

try: git rebase -i --root

--root

Rebase all commits reachable from <branch>, instead of limiting them with
an <upstream>.

This allows you to rebase the root commit(s) on a branch.  
When used with --onto, it will skip changes already contained in `<newbase>`   
(instead of `<upstream>`) whereas without --onto it will operate on every 
change. When used together with both --onto and --preserve-merges, all root 
commits will be rewritten to have `<newbase>` as parent instead.`