undo git amend

Sometimes one may want to undo a git amend. In my case, I push the commit to the remote, and then did an amend on the local side, which cause conflict. The reason is that git commit --amend creates a new commit and detaches the previous commit, and when you push to the remote there will be a conflict since it finds two different commits.

To undo amend:

1. find the <hash> of the original commit by running git reflog
2. run git reset --mixed <hash> to reset the commit to the original state

Difference between --hard, --soft, --mixed in git reset:

• --hard: reset the commit to the original state, throw away all changes
• --soft: reset the commit to the original state, but keep the changes in the working tree
• --mixed: reset the commit to the original state, but keep the changes in the working tree, and keep the changes in the index

Reference

• https://dev.to/flyingdot/git-magic-1-undo-git-amend-196g
• https://www.howtogeek.com/devops/how-does-git-reset-actually-work-soft-hard-and-mixed-resets-explained/#:~:text=1%20git%20reset%20--soft%2C%20which%20will%20keep%20your,files%20the%20same%20but%20unstages%20the%20changes.%20