Upgrade flate2 integration to v0.3.0

[Shnatsel]

It would be nice to upgrade flate2 to use v0.3.0 of zlib-rs, since it contains important fixes such as #165, #169, #172

I've attempted a naive bump from v0.2.1 to v0.3.0, but after running the flate2 roundtrip fuzzer I found that deflateInit2 now returns Z_VERSION_ERROR when called from flate2.

You can reproduce the issue by running the following command in flate2 repository with the attached file:

cargo +nightly fuzz run fuzz_gz_roundtrip /path/to/roundtrip_failing_input

roundtrip_failing_input.fake_extension_to_make_github_accept_upload.pdf

This will work fine with zlib-rs 0.2.1 but fail with 0.3.0, complaining about an assertion failure on this line:
https://github.com/rust-lang/flate2-rs/blob/6fbd6d21151d0948ed94be8ac99b412d30315109/src/ffi/c.rs#L325

[folkertdev]

I suspect you've missed

-    const ZLIB_VERSION: &'static str = "0.1.0\0";
+    const ZLIB_VERSION: &'static str = "1.3.0-zlib-rs-0.3.0\0";

in src/ffi/c.rs? You can now (via some macro magic) find the version string in our documentation https://docs.rs/libz-rs-sys/0.3.0/libz_rs_sys/fn.zlibVersion.html, though I don't think changes to the version will be relevant in the future.

With that line added, your example input works

     Running `fuzz/target/x86_64-unknown-linux-gnu/release/fuzz_gz_roundtrip -artifact_prefix=/home/folkertdev/rust/flate2-rs/fuzz/artifacts/fuzz_gz_roundtrip/ /home/folkertdev/Downloads/roundtrip_failing_input.fake_extension_to_make_github_accept_upload.pdf`
INFO: Running with entropic power schedule (0xFF, 100).
INFO: Seed: 595841439
INFO: Loaded 1 modules   (25753 inline 8-bit counters): 25753 [0x5d9bece1aaf0, 0x5d9bece20f89), 
INFO: Loaded 1 PC tables (25753 PCs): 25753 [0x5d9bece20f90,0x5d9bece85920), 
fuzz/target/x86_64-unknown-linux-gnu/release/fuzz_gz_roundtrip: Running 1 inputs 1 time(s) each.
Running: /home/folkertdev/Downloads/roundtrip_failing_input.fake_extension_to_make_github_accept_upload.pdf
Executed /home/folkertdev/Downloads/roundtrip_failing_input.fake_extension_to_make_github_accept_upload.pdf in 1 ms
***
*** NOTE: fuzzing was not performed, you have only
***       executed the target code on a fixed set of inputs.
***

where in the fuzzer's Cargo.toml I changed this line

-flate2 = { path = ".." }
+flate2 = { path = "..", default-features=false, features=["zlib-rs"] }

and in the main Cargo.toml I changed

-libz-rs-sys = { version = "0.2.1", optional = true, default-features = false, features = ["std", "rust-allocator"] }
+libz-rs-sys = { version = "0.3.0", optional = true, default-features = false, features = ["std", "rust-allocator"] }

Does that work on your machine?

[Shnatsel]

Ah, so I did! I did not realize changing that was required, thanks! It does work correctly now.

I'll open a PR to upgrade flate2 to v0.3.0

[Shnatsel]

PR is up: rust-lang/flate2-rs#428

[folkertdev]

seems like this is resolved and the updated version will be merged soon, so I'm closing this