upgrade to libz-sys 1.1.23, using libz-ng 2.2.4

This release makes some changes to the medium algorithm, see zlib-ng/zlib-ng#1938

Author: folkertdev

.github/workflows/checks.yaml

@@ -31,6 +31,7 @@ jobs:
       # wasm32-wasip1 (std for wasip2 is unstable)
       WASI_SDK_PATH: /tmp/wasi-sdk-24.0-x86_64-linux
       CC_wasm32_wasip1: /tmp/wasi-sdk-24.0-x86_64-linux/bin/clang
+      CXX_wasm32_wasip1: /tmp/wasi-sdk-24.0-x86_64-linux/bin/clang++
       AR_wasm32_wasip1: /tmp/wasi-sdk-24.0-x86_64-linux/bin/llvm-ar
       CARGO_TARGET_WASM32_WASIP1_RUNNER: "wasmtime --dir /home/runner/work/zlib-rs/zlib-rs/test-libz-rs-sys --dir /tmp/"
       CARGO_TARGET_WASM32_WASIP1_RUSTFLAGS: "-Ctarget-feature=+simd128"
@@ -60,12 +61,12 @@ jobs:
           - target: "i686-unknown-linux-gnu"
             os: ubuntu-latest
             codecov: true
-            packages: gcc-i686-linux-gnu
+            packages: gcc-i686-linux-gnu g++-i686-linux-gnu
 
           - target: "s390x-unknown-linux-gnu"
             os: ubuntu-latest
             codecov: false
-            packages: gcc-s390x-linux-gnu qemu-user qemu-user-static
+            packages: gcc-s390x-linux-gnu g++-s390x-linux-gnu qemu-user qemu-user-static
 
           - target: "wasm32-wasip1"
             os: ubuntu-latest
@@ -470,7 +471,7 @@ jobs:
       - name: Install gcc
         if: ${{ contains(matrix.target, 'windows') }}
         run: |
-          sudo apt-get install gcc-mingw-w64-x86-64
+          sudo apt-get install gcc-mingw-w64-x86-64 g++-mingw-w64-x86-64
           x86_64-w64-mingw32-gcc --help
       - name: Install cargo-nextest
         uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2

Cargo.lock

@@ -33,8 +33,7 @@ opt-level = 1 # required for the tail calls in inflate to optimize
 
 [workspace.dependencies]
 libloading = "0.8.1"
-# FIXME: later libz-sys versions change the output of medium compression slightly.
-libz-sys = { version = "=1.1.21", default-features = false, features = ["zlib-ng"] } # use libz-ng in libz compat mode
+libz-sys = { version = "1.1.23", default-features = false, features = ["zlib-ng"] } # use libz-ng in libz compat mode
 arbitrary = { version = "1.0" }
 quickcheck = { version = "1.0.3", default-features = false, features = [] }
 

Cargo.toml

@@ -24,7 +24,7 @@ features = ["arbitrary-derive"]
 
 [dependencies]
 libc = "0.2.151"
-libz-ng-sys = "=1.1.21"
+libz-ng-sys = "1.1.23"
 libloading = "0.8.1"
 crc32fast = "1.3.2"
 rstest = "0.23.0"

fuzz/Cargo.toml

@@ -1974,7 +1974,7 @@ mod fuzz_based_tests {
             &input,
             DeflateConfig::default(),
             &[
-                120, 156, 19, 99, 24, 5, 12, 12, 12, 172, 32, 18, 0, 24, 45, 0, 28,
+                120, 156, 19, 99, 24, 5, 12, 12, 12, 172, 160, 80, 0, 0, 24, 45, 0, 28,
             ],
         )
     }
@@ -2600,7 +2600,7 @@ fn test_gzip_deflate_config() {
 	            0,
 	        ],
 	        name: CString::default(),
-	        comment: CString::from(c"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"),
+	        comment: CString::new(b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff").unwrap(),
 	        hcrc: 1548508252,
 	    },
 	};
@@ -2626,7 +2626,7 @@ fn test_gzip_deflate_config() {
                 config.mem_level,
                 config.strategy as i32,
                 zlibVersion(),
-                size_of::<z_stream>() as c_int,
+                core::mem::size_of::<z_stream>() as c_int,
             )
         };
 

test-libz-rs-sys/src/deflate.rs

@@ -1302,7 +1302,7 @@ pub(crate) struct State<'a> {
     //
     // Insert new strings in the hash table only if the match length is not
     // greater than this length. This saves time but degrades compression.
-    // max_insert_length is used only for compression levels <= 3.
+    // max_insert_length is used only for compression levels <= 6.
     // define max_insert_length  max_lazy_match
     /// Attempt to find a better match only when the current match is strictly smaller
     /// than this value. This mechanism is used only for compression levels >= 4.

zlib-rs/src/deflate.rs

@@ -230,8 +230,11 @@ fn insert_match(state: &mut State, mut m: Match) {
         return;
     }
 
-    // Insert new strings in the hash table
-    if state.lookahead >= WANT_MIN_MATCH {
+    // Insert new strings in the hash table only if the match length
+    // is not too large. This saves time but degrades compression.
+    if usize::from(m.match_length) <= 16 * state.max_insert_length()
+        && state.lookahead >= WANT_MIN_MATCH
+    {
         m.match_length -= 1; /* string at strstart already in table */
         m.strstart += 1;