One of my commits on github appear as a different user inside my repo

[nathub]

Code Security - SSH keygen authentication mistake?

What could have caused this mystery user to appear in my git history, on one of my commits? Can I fix this, and can I remove them from the git history? All the commits were written by me on my computer.

Sorry I'm still new to actually using github personally.

My little github repo for testing github and learning pascal, says I have two contributors. One is me, the other is "weinliu", a Github user that has nothing to do with my repo. I don't know them and I don't know how they are attributed to my repo.

When I view the Contributors, it lists they did one commit in Oct 24th, 2025. However when I view that commit, I remember doing that one. And when I view Weinliu's profile, it says they have no activity in October. I just made this repo, I'm the only person with access.

What could have caused this? How do I ensure this isn't an issue? I generated my SSH keys normally, with ssh-keygen in the ed20-whatever format. I'm baffled how something was attributed to this user.

This is my repo: https://github.com/nathub/Small-Pascal-Example-Project

This is the user that is somehow attributed to my commit: https://github.com/weinliu (no activity in October)

Important to note, I have commits before and after this mystery person's commit, that ARE correctly attributed to me. I haven't adjusted my SSH key or anything. First thing I thought was that I copied and pasted an SSH command when generating the key and included someone else's email? But there's no way since it worked correctly afterwards (on both my computers).

[nathub]

I am an idiot

Using a graphical git client I opened the repo's history and found the user of that commit:
My other commits say "Nathan H" , but that one commit says "Nathan".

When I open it it takes me to my mail client and tries to send to "nathan@localhost.localdomain"

So I guess I did that.
Not clear why that user has that set as their github email? Or what happened there. But clearly I must've reset the git user on Oct 24th and made a commit, before fixing it at some later time.

My mistake

[nathub]

I'd like to know if I can fix this in my history ... atleast so the github doesnt link to that random user's account. But I know it's more likely best left alone.

Just so weird the mailto email of localdomain is parsed on github, I'd think it'd just say unknown user or something.