threads / discuss / 10088

Obliterating a commit

Subject: Obliterating a commit

## tl;dr

3 messages between Sep 30, 2007 and Sep 30, 2007.

replies: 2people: 2as markdown or json

Wincent Colaiuta· Sep 30, 2007, 11:32 UTC · lore

A couple of days ago I mistakenly checked in a file that had some confidential information in it. I immediately realized and amended my commit, and this is a local repository whose contents won't be visible until I push them out.

So how do I *really* get rid of the that commit before publishing? I couldn't find any porcelain or plumbing to do this. Do I have to manually destroy it? ie. wind back the HEAD, manually remove the commit object, the corresponding tree object, the corresponding file blobs, and probably manually remove the entry from the reflog as well?

Is there a "shortcut" wherein I can somehow mark this commit and its related tree and file blobs as unreachable, and then use git-prune to erradicate them?

Cheers, Wincent

Matthias Kestenholz· Sep 30, 2007, 12:15 UTC · re: Wincent Colaiuta · lore

Re: Obliterating a commit

Hello,

2007/9/30, Wincent Colaiuta <win@wincent.com>:

Show 11 quoted lines

> A couple of days ago I mistakenly checked in a file that had some
> confidential information in it. I immediately realized and amended my
> commit, and this is a local repository whose contents won't be
> visible until I push them out.
>
> So how do I *really* get rid of the that commit before publishing? I
> couldn't find any porcelain or plumbing to do this. Do I have to
> manually destroy it? ie. wind back the HEAD, manually remove the
> commit object, the corresponding tree object, the corresponding file
> blobs, and probably manually remove the entry from the reflog as well?
>

If you use ssh to push your changes (that is, you are not copying or rsyncing packfiles), only commits, trees and blobs, which are reachable through the DAG will be published. Commits and Blobs which are only reachable through your reflog are not published, since the reflog only applies to your local repository.

The simplest thing you could do is remove the reflog for HEAD and refs/heads/master respectively your current branch and run 'git prune' afterwards (if you have not repacked already, otherwise you'd need to run 'git repack -a -d' or 'git gc' to get rid of blobs inside your packfile.

> Is there a "shortcut" wherein I can somehow mark this commit and its
> related tree and file blobs as unreachable, and then use git-prune to
> erradicate them?
>

You don't need to mark anything -- it's sufficient that the blob with the confidential information is only reachable through the reflog (which you need to remove, obviously, if you want to get rid of the blob locally too)

Cheers, Matthias

Wincent Colaiuta· Sep 30, 2007, 14:13 UTC · re: Matthias Kestenholz · lore

Re: Obliterating a commit

El 30/9/2007, a las 14:15, Matthias Kestenholz escribió:

Show 7 quoted lines

> If you use ssh to push your changes (that is, you are not copying
> or rsyncing packfiles), only commits, trees and blobs, which are  
> reachable
> through the DAG will be published. Commits and Blobs which are only
> reachable through your reflog are not published, since the reflog  
> only applies
> to your local repository.

Ah, this is good to know. Yes, I do principally publish by pushing to a central repo, but I wanted to really destroy the objects just in case in the future I or somebody else ever clones my local repo.

Show 6 quoted lines

> The simplest thing you could do is remove the reflog for HEAD and
> refs/heads/master respectively your current branch and run 'git prune'
> afterwards (if you have not repacked
> already, otherwise you'd need to run 'git repack -a -d' or 'git gc'  
> to get
> rid of blobs inside your packfile.

Thanks very much, Matthias. Blowing away those reflogs and running git-prune worked and it's doesn't require too much fiddling.

Cheers, Wincent