sanity check that symbol resolution functions correctly

Author: folkertdev

.github/workflows/checks.yaml

@@ -282,7 +282,7 @@ jobs:
           LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
         working-directory: libz-rs-sys-cdylib
         run: |
-          cargo build --release --target ${{matrix.target}} --no-default-features --features="rust-allocator"
+          cargo build --release --target ${{matrix.target}} --no-default-features --features="export-symbols,rust-allocator"
           cc -o zpipe zpipe.c target/${{matrix.target}}/release/deps/libz_rs.so
           ./zpipe < Cargo.toml | ./zpipe -d > out.txt
           cmp -s Cargo.toml out.txt
@@ -291,7 +291,7 @@ jobs:
           LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
         working-directory: libz-rs-sys-cdylib
         run: |
-          cargo build --release --target ${{matrix.target}} --no-default-features
+          cargo build --release --target ${{matrix.target}} --no-default-features --features="export-symbols"
           cc -DNO_STD -o zpipe zpipe.c target/${{matrix.target}}/release/deps/libz_rs.so
           ./zpipe < Cargo.toml | ./zpipe -d > out.txt
           cmp -s Cargo.toml out.txt

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

@@ -49,6 +49,22 @@ macro_rules! extract_error_message {
     };
 }
 
+/// a bit of a sanity check that nothing weird happened with symbol resolution
+#[cfg(not(miri))]
+#[cfg(test)]
+#[test]
+fn zlib_rs_is_not_zlib_ng() {
+    use std::ffi::CStr;
+
+    unsafe {
+        let rs = CStr::from_ptr(libz_rs_sys::zlibVersion());
+        assert!(rs.to_str().unwrap().contains("zlib-rs"));
+
+        let ng = CStr::from_ptr(libz_sys::zlibVersion());
+        assert!(ng.to_str().unwrap().contains("zlib-ng"));
+    }
+}
+
 #[cfg(test)]
 mod null {
     use core::mem::MaybeUninit;