Why is this strange? I never worked in a project where fixes required tests beyond some QA guy/gal stating "it works, done".
> MariaDB includes test cases for all fixed bugs.
It's not something I've practiced much myself, but writing a test case to reproduce the bug and then fix the bug seems like a more reasonable form of TDD in my head.
I've seen it once when reporting a bug to another team I worked alongside, where I was stress testing a new feature and found said bug. Instead of having to run the stress test, they wrote a unit test to reproduce it at a much smaller scale and then had a much smaller feedback loop to ensure it worked after they fixed it.