corrupted repo and "git push --mirror"

This is probably a stupid question, but in the spirit of extreme paranoia *and* because it's kinda hard to "try it and see", I'm going to risk the ridicule :)

Gitolite has mirroring support now, basically using "git push --mirror". The question I was asked, and I couldn't *confidently* answer, was: what happens if the source repo suffers some corruption for some reason? Does the corruption propagate?

I suspect not, but I'd appreciate corraboration and if anyone can sat what actually will happen that'd be great.

Secondary question: what happens if the receiving repo is corrupt?

Thanks!