How to undo a failed rebase
---
If a rebase you tried went through but did the wrong thing, it's too late to
run `git rebase --abort`. So, what to do? That's where Git's [reflog][reflog]
comes in.  Whenever you change your branch in some way, it saves the state of
the branch before your operation, so a reflog is basically a history of what
your branch looked like before/after each operation.

Suppose you botched a rebase by accidentally removing an important commit. The
most generic way of undoing this if you spot it immediately is rather simple:

	git reset --hard @{1}

You may have to escape the curly braces so your shell doesn't try to eat them.

It gets more complicated if you perform a couple of commits before you spot
the problem. In this case, we'll do almost the same thing, but save the
botched state with the additional commits and, once we've unbotched things,
transplant the new commits over. For that we use... you guessed it... rebase.

Suppose you're dealing with the branch master and made 4 good commits after
your botched rebase (and none of them were merges. You'd better not have to
fix complicated merges in this situation because rebase eliminates merges).
Then you go like this:

	# We're going to create the goal situation in a new branch
	git checkout -b fixed-branch
	git rebase --onto master@{1} HEAD~4
	# If conflicts occur, fix and git rebase --continue etc.
	# In case things are okay now, overwrite master with this
	git checkout master
	git reset --hard fixed-branch
	git branch -d fixed-branch

[reflog]: http://git.or.cz/man/git-reflog