Go back in history to an undamaged version?

I have a corrupted loose object.

I tried checkout, revert, rebase and may be few other things to go to an original commit.
In each case I ran git fsck and still had the same problem:

  • Repair corrupted git repository
  • git svn: Delta source ended unexpectedly
  • How do I prevent my git from corrupting?
  • How to recover files from a corrupted git working folder
  • Rebuild loose missing tree in Git when there are no other missing objects
  • Git pull without history
  • > git fsck 
    error: corrupt loose object '25a196217ebb6e341909205575f491022eafc4d9'
    fatal: loose object 25a196217ebb6e341909205575f491022eafc4d9 (stored in .git/objects/25/a196217ebb6e341909205575f491022eafc4d9) is corrupt
    

    is there a way to get rid of corrupted objects without simply deleting .git? I don’t have another backup so I can’t replace the corrupted object.

    It’s a more narrow question that arose from this git "error: corrupt loose object" after moving a directory

    update (1):

    > git gc
    Counting objects: 747, done.
    Delta compression using up to 8 threads.
    error: corrupt loose object '25a196217ebb6e341909205575f491022eafc4d9'
    fatal: loose object 25a196217ebb6e341909205575f491022eafc4d9 (stored in .git/objects/25/a196217ebb6e341909205575f491022eafc4d9) is corrupt
    error: failed to run repack
    

    update (2):
    this didn’t work either Remove file from git repository (history)

    update (3):
    cloning didn’t work:

    > git clone ../dynamicsCode_good/ .
    Cloning into ....
    done.
    error: corrupt loose object '25a196217ebb6e341909205575f491022eafc4d9'
    fatal: loose object 25a196217ebb6e341909205575f491022eafc4d9 (stored in .git/objects/25/a196217ebb6e341909205575f491022eafc4d9) is corrupt
    

    the . directory is empty

    update (4):
    removing a corrupted object.

    > git --version
    git version 1.7.5.4
    
    
    > rm -f .git/objects/25/a196217ebb6e341909205575f491022eafc4d9
    13:42:57 ~/Dropbox/work/dev/dynamicsCode_torek 
    > git fsck --full
    missing blob 25a196217ebb6e341909205575f491022eafc4d9
    dangling tree 64a970c878fef7deeeb4ce2ffc5e6234a72894ad
    dangling tree 528e6c121fb8e56097462b2ebb9ec4de66388ce2
    

    first (initial) comment. this comment doesn’t even have the corrupted file.

    > git log |tail -5
    commit 150ceebafb9c20769386cc7ffba07f6e6565fae6
    Author: Kirill ...gmail.com>
    Date:   Tue Sep 27 22:51:15 2011 -0400
    
        state takes input as input
    checkout:
    
    > git checkout -b 150ceebafb9c20769386cc7ffba07f6e6565fae6
    Switched to a new branch '150ceebafb9c20769386cc7ffba07f6e6565fae6'
    
    > git gc
    Counting objects: 783, done.
    error: unable to find 25a196217ebb6e341909205575f491022eafc4d9
    Compressing objects: 100% (776/776), done.
    fatal: unable to read 25a196217ebb6e341909205575f491022eafc4d9
    error: failed to run repack
    > git fsck --full
    broken link from    tree 4668817140320ad2e04aa946d95dec2c3885d97b
                  to    blob 25a196217ebb6e341909205575f491022eafc4d9
    missing blob 25a196217ebb6e341909205575f491022eafc4d9
    dangling tree 64a970c878fef7deeeb4ce2ffc5e6234a72894ad
    dangling tree 528e6c121fb8e56097462b2ebb9ec4de66388ce2
    

    I also tried unpacking the only object in the .git/objects/pack/ directory. didn’t help.

    I also cloned this state into a new directory:

    > git gc
    Counting objects: 662, done.
    error: unable to find 25a196217ebb6e341909205575f491022eafc4d9
    Compressing objects: 100% (656/656), done.
    fatal: unable to read 25a196217ebb6e341909205575f491022eafc4d9
    error: failed to run repack
    14:40:34 ~/Dropbox/work/dev/dynamicsCode_torek_commit_clone 
    > git fsck 
    broken link from    tree b5ab6b287804d5069a3c8648ace38d9d9feac1a5
                  to    blob 25a196217ebb6e341909205575f491022eafc4d9
    dangling commit dad8edc620248d3911b7b1c0a99608a64e0288a3
    missing blob 25a196217ebb6e341909205575f491022eafc4d9
    dangling tree 64a970c878fef7deeeb4ce2ffc5e6234a72894ad
    dangling commit ae2b2a9edb744d9e91aa78891c849d5a0040ea94
    dangling commit 32ed79bd4ac70b118d046cb6093a4710562e95ba
    dangling commit 7e45ef0c6ffc46401b1f82bcbf0f7e843abf9e31
    dangling tree 528e6c121fb8e56097462b2ebb9ec4de66388ce2
    14:40:40 ~/Dropbox/work/dev/dynamicsCode_torek_commit_clone 
    > git branch 
    * 150ceebafb9c20769386cc7ffba07f6e6565fae6
    

    didn’t help either.

    The corrupted file is tags from ctags. I don’t need it. it’s strange that i can’t rebuild git without that file. Most importantly, from all my research I don’t see neither how it can be done nor why it’s not possible.

    update (5):
    checkout without branching

    > git checkout 150ceebafb9c20769386cc7ffba07f6e6565fae6
    Note: checking out '150ceebafb9c20769386cc7ffba07f6e6565fae6'.
    
    You are in 'detached HEAD' state. You can look around, make experimental
    changes and commit them, and you can discard any commits you make in this
    state without impacting any branches by performing another checkout.
    
    If you want to create a new branch to retain commits you create, you may
    do so (now or later) by using -b with the checkout command again. Example:
    
      git checkout -b new_branch_name
    
    HEAD is now at 150ceeb... state takes input as input
    16:41:40 ~/Dropbox/work/dev/dynamicsCode_torek_commit 
    > git fsck --full
    broken link from    tree 4668817140320ad2e04aa946d95dec2c3885d97b
                  to    blob 25a196217ebb6e341909205575f491022eafc4d9
    missing blob 25a196217ebb6e341909205575f491022eafc4d9
    dangling tree 64a970c878fef7deeeb4ce2ffc5e6234a72894ad
    dangling tree 528e6c121fb8e56097462b2ebb9ec4de66388ce2
    

  • git add * (asterisk) vs git add . (period)
  • How do I fix checking out HEAD^ in git
  • Using GIT_SSH_COMMAND in Git for Windows
  • How to make git output usage for any command?
  • How to contribute to someone else's repository?
  • Git Stash Failed
  • One Solution collect form web for “Go back in history to an undamaged version?”

    If you remove the corrupted object manually, git will generally let you get at everything else. I deliberately corrupted a git blob (just forced a few bad bytes in the front) and got the following:

    $ git fsck
    fatal: object bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad is corrupted
    $ git gc
    Counting objects: 23, done.
    error: unable to unpack bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad header
    error: inflateEnd: failed
    Delta compression using up to 2 threads.
    Compressing objects: 100% (12/12), done.
    fatal: object bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad is corrupted
    error: failed to run repack
    $ git fsck --full
    fatal: object bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad is corrupted
    $ rm -f .git/objects/bd/1b260b0ef92d1a219e1183953fa1ac7cdb4cad
    $ git fsck --full
    broken link from    tree a3070cb66fd169e1443867a8bb137a44103c9f24
                  to    blob bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad
    missing blob bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad
    $ git cat-file -p 2418b6ba8fd0289933c9351260a272b8e410867f
    tree a3070cb66fd169e1443867a8bb137a44103c9f24
    parent 8d945134b0cead535d66af29c8eb4228b5dc3763
    author [redacted] 1333789753 -0600
    committer [redacted] 1333789753 -0600
    
    test corrupted object
    $ git checkout 2418b6ba8fd0289933c9351260a272b8e410867f
    error: git checkout-index: unable to read sha1 file of morefile (bd1b260b0ef92d1a219e1183953fa1ac7cdb4cad)
    D   morefile
    Note: checking out '2418b6ba8fd0289933c9351260a272b8e410867f'.
    
    You are in 'detached HEAD' state. ...
    

    Note, somewhere along the way it re-pointed the branch master to a previous “good” commit (not the immediately-previous one, and I have no idea why) so you may then have to repair your commit history, etc. But everything was there, except for the missing file “morefile” whose blob I corrupted. (I restored it from a backup copy I made in advance and was even able to get the file back, with git checkout -- morefile. You could mv the corrupted blob somewhere and see if you can recover some of your data from it.)

    I’d certainly back up the broken git repo first, Just In Case. 🙂

    Git Baby is a git and github fan, let's start git clone.