A Study of Undefined Behavior Across Foreign Function Boundaries in Rust Libs
arxiv.org
arxiv.org
Flate2 is an odd crate so I'm not too surprised to hear there's issues with it.
It seems unusual to rely on an FFI for something that isn't extremely intricate, broad, or brittle like syscalls / drivers / runtimes, I'd think that one zlib implementation would be as good as another, but maybe I'm naive.
Thankfully crates makes it pretty plain who would see fit to build on top of that.