Undo git filter-branch

Question

I accidentally delete a file from my repo using git filter-branch:

git filter-branch -f --index-filter 'git rm --cached --ignore-unmatch images/thumb/a.JPG' HEAD

How can I undo this? Is it possible? i.e. is the file permanently deleted?

Answer 1

When you use git filter-branch, a backup file is created in

refs/original/refs/heads/master

If you used the command in branch master. You can check if you have the backup in .git/refs directory. With this in mind, you can use this backup to recover your files with:

git reset --hard refs/original/refs/heads/master