corruption - Repair corrupted Git repository

Question

My Git repository got corrupted after a couple of hard reboots due to power supply issues and now I'm unable to fix it (I was in the middle of staging some files at the last power failure):

$ git status
fatal: failed to read object 3d18855708b0f127d40c13c679559d7679228b69: Invalid argument
$ git fsck
fatal: failed to read object 24377c609184c192f3f3c1733bac7115c1080758: Invalid argument
$ git branch -a
(...works, lists branches...)
$ git checkout someotherbranch
fatal: failed to read object 3d18855708b0f127d40c13c679559d7679228b69: Invalid argument
$ git log
fatal: failed to read object 3d18855708b0f127d40c13c679559d7679228b69: Invalid argument
$ git log someotherbranch
(...works, shows commits...)

So, as you can see, my current branch is pretty screwed up, and I don't seem to be able to fix it. What can I try to repair this?

Answer 1

My solution for a similar situation was to replace a hash of the damaged object in .git/refs/heads/my-working-branch with a hash of previous commit (which can be found in .git/logs/HEAD).