Dear open source committers and developers: never, EVER do this.
https://ariel-miculas.github.io/How-I-got-robbed-of-my-first-kernel-contribution/
Newcomers need encouragement, mentorship, and support. Never dismiss days of work. Give them feedback and send them back to do it correctly.
OpenBSD is actually pretty good at massaging newcomers into producing solid patches, if you can ignore the haters on their mailing lists.
(blog post found via @vaurora, it's an excellent writeup of a problem I've seen too many times.)