Merge 'v1.6.1' into 'master' (#721)

CHANGELOG.md

@@ -1,3 +1,8 @@
+# 1.6.1 (July 13, 2024)
+
+This release fixes a bug where `Bytes::is_unique` returns incorrect values when
+the `Bytes` originates from a shared `BytesMut`. (#718)
+
 # 1.6.0 (March 22, 2024)
 
 ### Added

Cargo.toml

@@ -4,7 +4,7 @@ name = "bytes"
 # When releasing to crates.io:
 # - Update CHANGELOG.md.
 # - Create "v1.x.y" git tag.
-version = "1.6.0"
+version = "1.6.1"
 edition = "2018"
 rust-version = "1.39"
 license = "MIT"

src/bytes_mut.rs

@@ -1780,7 +1780,7 @@ static SHARED_VTABLE: Vtable = Vtable {
     clone: shared_v_clone,
     to_vec: shared_v_to_vec,
     to_mut: shared_v_to_mut,
-    is_unique: crate::bytes::shared_is_unique,
+    is_unique: shared_v_is_unique,
     drop: shared_v_drop,
 };
 
@@ -1843,6 +1843,12 @@ unsafe fn shared_v_to_mut(data: &AtomicPtr<()>, ptr: *const u8, len: usize) -> B
     }
 }
 
+unsafe fn shared_v_is_unique(data: &AtomicPtr<()>) -> bool {
+    let shared = data.load(Ordering::Acquire);
+    let ref_count = (*shared.cast::<Shared>()).ref_count.load(Ordering::Relaxed);
+    ref_count == 1
+}
+
 unsafe fn shared_v_drop(data: &mut AtomicPtr<()>, _ptr: *const u8, _len: usize) {
     data.with_mut(|shared| {
         release_shared(*shared as *mut Shared);

tests/test_bytes.rs

@@ -1173,6 +1173,15 @@ fn shared_is_unique() {
     assert!(c.is_unique());
 }
 
+#[test]
+fn mut_shared_is_unique() {
+    let mut b = BytesMut::from(LONG);
+    let c = b.split().freeze();
+    assert!(!c.is_unique());
+    drop(b);
+    assert!(c.is_unique());
+}
+
 #[test]
 fn test_bytesmut_from_bytes_static() {
     let bs = b"1b23exfcz3r";