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Here's something that regularly happens to me at work:

[user@macmini ~/code/project $] git add .
[user@macmini ~/code/project $] git commit -m "Fixed whatever bug"
[master 93a3c47] Fixed whatever bug
 3 files changed, 290 insertions(+)
 create mode 100644 .DS_Store
 create mode 100755 some-code.js
 create mode 100755 some-other-code.js

As you can see, I've accidentally committed the .DS_Store file which macOS like creating after you open a folder in Finder.

In this case I usually clone the repo again, copy and paste my new code in, and commit again without the .DS_Store. But I know it's not the clean way to do it.

So, how can I cleanly undo a commit? I've tried git reset --hard HEAD but it deletes my new files too.

Chef Tony
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  • https://stackoverflow.com/search?q=%5Bgit%5D+undo+commit – phd Dec 16 '18 at 19:37
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    have a look to branches, this will allow you to do all kinds of test and if you'r not satisfied with the branch you'll forgtet it, if you are satisfied you will merge it to master. Do has many branches as the number of solutions you try, don't delete the branches too quickly it doesn't cost but ther might still be some interesting stuff there, only once you have a solution you like and merged it to your master stream, remove the other test branches. – jo_ Dec 16 '18 at 19:50

1 Answers1

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git reset HEAD~1

This will "undo" your last commit without touching your working directory (any our files). It is the same as git reset --mixed HEAD~1. You can also do git reset --soft HEAD~1, which will leave all the files as marked for commit.

If you mostly like your commit, but just want to make a small change to its content or its commit message, you can amend the current commit instead:

git rm .DS_Store
git commit --amend

This will prompt you for editing the commit message (you may leave it unchanged), and will then modify the commit with your changes.

git reset basically means "move my current branch to the given commit", and HEAD~1 means "the previous commit". The only problem with your command was that it included --hard, which says "oh, also make all my files look like they did in that commit".

A branch is just a label that references a particular commit; it can be freely moved around (although if you've pushed a branch and you move it backwards, you'll get problems when you try to push or pull).

If you ever feel the need to re-clone a repository, there is almost always a better solution in git. Commits in git, and the files in them can be undone, redone, moved, and sometimes even resurrected. Also, commits are local: no one sees them until you've pushed.

Aasmund Eldhuset
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