Man, I thought zero days and secret backdoors were bad enough. Now we have to worry about manufactured hash collisions in all our repos' files dating back forever?

That seems like an overkill. Couldn't you combine the hash together with the date to obtain uniqueness?

The date isn't really meaningful since it can be set to anything on a file. But if you can force two dissimilar files to have the same hash, you can combine that with some other attack to inject it into some sort of chain of trust, whether it's git or some other type of checksum based system. Then combine that with a SolarWinds like attack and even if they try to revert to something from years earlier, they can't guarantee that the rollback files are still unaltered unless they had multiple hashes to compare it to or diffed it manually. But multiply that by X thousand files over Y commits during Z years and it would be very difficult to detect.

I do not remember jgit internals, but its API is pretty bad. I always assumed it was some kind of throwaway PoC suddenly turned popular.

> some kind of throwaway PoC suddenly turned popular

Wow, that description feels spot on.