Answer by Colin Hebert for How to recover a dropped stash in Git?

If you want to restash a lost stash, you need to find the hash of your lost stash first.

As Aristotle Pagaltzis suggested a git fsck should help you.

Personally I use my log-all alias which show me every commit (recoverable commits) to have a better view of the situation :

git log --graph --decorate --pretty=oneline --abbrev-commit --all $(git fsck --no-reflogs | grep commit | cut -d'' -f3)

You can do an even faster search if you're looking only for "WIP on" messages.

Once you know your sha1, you simply change your stash reflog to add the old stash :

git update-ref refs/stash ed6721d

You'll probably prefer to have an associated message so a -m

git update-ref -m "$(git log -1 --pretty=format:'%s' ed6721d)" refs/stash ed6721d

And you'll even want to use this as an alias :

restash = !git update-ref -m $(git log -1 --pretty=format:'%s' $1) refs/stash $1