在'git push --mirror'之后恢复已删除的分支

Question

My organization has a remote repository on GitHub that's a fork off of another. I've made a clone on my local machine as well as created a local branch, 'test'. The following is a list of commands that followed:

git fetch origin '+refs/heads/*:refs/remotes/origin/*'
git push --mirror
git push --all

What followed next was nothing short of a nightmare. Any branch on the remote that wasn't checked out on my local machine was deleted on the repository. I've done git branch -a but that only shows, for the remote, branches that had existed on my local copy. I've done git reflog show but that only shows logs on the current branch HEAD . Doing git fsck shows 6 'dangling commits' and 2 'dangling blobs'. Prior to doing git push --mirror the branch had 16 branches, 5 of which were created by our organization and the rest were from the original fork. I understand that similar, if not the same, questions have been asked before but at this point none of them are making sense. My utmost respect and highest gratitude to anyone who can prevent me from getting fired.

Answer 1

There's a few things to try. These first two approaches will help you recover the SHA1s of things that used to be branch tips. But one thing that will be hard to recover is the names of the missing branches, unless that was previously known.

1. If some of the branches were recently visited by you, your reflog will have their tips:

    git reflog 

2. You can create a list of all the dangling and lost-and-found commits with:

    git fsck --full --no-reflogs --unreachable --lost-found | \\ grep commit | \\ cut -d" " -f3 | \\ xargs -n 1 git log -n 1 --pretty=oneline > .git/lost-found.txt 

   and then see if the commits match the missing branches.

If you know the name of a branch you want to recover, then you can also try:

3. You can use git-resurrect.sh in the contrib directory to attempt to "resurrect" past branches by scanning your reflog and other sources. This is extremely slow and can take a long time for large repositories.

Answer 2

If you have filesystem access to the remote that you pushed to, you can recover the deleted branches from MYREPO.git/info/refs .

The contents looks something like this.

2ef208a632946dd4b5fd6f124a7fd6fc1c2ab87e        refs/heads/foo-feature
7325d39f52d6663e33f360b3bd666300ce2c52b0        refs/heads/bar-feature

For each branch you want to recover, create a file in your local repo.

$ echo 2ef208a632946dd4b5fd6f124a7fd6fc1c2ab87e > .git/refs/heads/foo-feature

Then, push your newly-recovered branches back to the server.

$ git push --all