How to restore git history

Question

One of our developers copied a file from one branch to another and rewrote the file's history. What is the best way to restore it.

   original__________________________________________________(commits d)____(commits e)___(no commit history for a, b, c in master)
    |                                            |
    |                                         (copied)
    |                                            |
    |                                            |
    |__(commits a)__(commits b)___(commits c)_____

copied file content from another branch and committed it in master, move would have kept the history intact I believe — ir2pid, Mar 15 '18 at 14:09
changes and commit messages of a, b, c won't be visible on original branch. From original branch(master) will see that everything done in (a,b,c,d) in one commit 'd'. — ir2pid, Mar 15 '18 at 15:45
Not an exact duplicate, but see https://stackoverflow.com/q/48294526/1256452 — torek, Mar 15 '18 at 18:46

score 2 · Answer 1 · answered Mar 15 '18 at 15:35

Make a new branch from the original. This is your backup with every commit after the file was copied.

git checkout -b backup

Now reset original to the last commit before the file was copied over.

git checkout original && git reset SHA --hard

Merge the branch with commits a-c into original.

git merge branchname

Check out your backup and rebase it

git checkout backup && git rebase original

You will have a merge conflict telling you 'both added x`, resolve this conflict and continue the rebase.

Now go back to original and merge the backup back

git checkout original && git merge backup

This should do it.

How to restore git history

1 Answers1