Git: Reflog & Lost Commits

Original chapter reference: Chapter 51: Reflog - Restoring commits not shown in git log. The command options and documentation recipes below are fully transcribed from Git Notes for Professionals.

Section 51.1: Recovering from a bad rebase

Suppose that you had started an interactive rebase:

git rebase --interactive HEAD~20

and by mistake, you squashed or dropped some commits that you didn't want to lose, but then completed the rebase. To recover, do git reflog, and you might see some output like this:

aaaaaaa HEAD@{0} rebase -i (finish): returning to refs/head/master
bbbbbbb HEAD@{1} rebase -i (squash): Fix parse error
...
ccccccc HEAD@{n} rebase -i (start): checkout HEAD~20
ddddddd HEAD@{n+1} ...
...

In this case, the last commit, ddddddd (or HEAD@{n+1}) is the tip of your pre-rebase branch. Thus, to recover that commit (and all parent commits, including those accidentally squashed or dropped), do:

$ git checkout HEAD@{n+1}

You can then create a new branch at that commit with git checkout -b [branch]. See Branching for more information.