From 6b4b0eda2980f09df18380c80f8ae6109ae70d83 Mon Sep 17 00:00:00 2001
From: Emily Crandall Fleischman <emilycf@mit.edu>
Date: Fri, 12 Jul 2024 19:09:46 -0400
Subject: [PATCH 1/2] Fix `Bytes::is_unique` when created from shared
 `BytesMut` (#718)

The `is_unique` entry in the vtable for `Bytes` created from a shared
`BytesMut` just called the `shared_is_unique` function from the `bytes`
module. However, that function dereferences the `data` argument` as
`bytes::Shared`, but the actual underlying type is `bytes_mut::Shared`.
---
 src/bytes_mut.rs    | 8 +++++++-
 tests/test_bytes.rs | 9 +++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/bytes_mut.rs b/src/bytes_mut.rs
index 282aaa710..2342077d2 100644
--- a/src/bytes_mut.rs
+++ b/src/bytes_mut.rs
@@ -1698,7 +1698,7 @@ unsafe fn rebuild_vec(ptr: *mut u8, mut len: usize, mut cap: usize, off: usize)
 static SHARED_VTABLE: Vtable = Vtable {
     clone: shared_v_clone,
     to_vec: shared_v_to_vec,
-    is_unique: crate::bytes::shared_is_unique,
+    is_unique: shared_v_is_unique,
     drop: shared_v_drop,
 };
 
@@ -1732,6 +1732,12 @@ unsafe fn shared_v_to_vec(data: &AtomicPtr<()>, ptr: *const u8, len: usize) -> V
     }
 }
 
+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);
diff --git a/tests/test_bytes.rs b/tests/test_bytes.rs
index 84c3d5a43..b2135905d 100644
--- a/tests/test_bytes.rs
+++ b/tests/test_bytes.rs
@@ -1172,3 +1172,12 @@ fn shared_is_unique() {
     drop(b);
     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());
+}

From fd13c7dcdb840653bf81294d141da77d3f1f9e1f Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Sat, 13 Jul 2024 07:45:33 +0000
Subject: [PATCH 2/2] chore: prepare bytes v1.6.1 (#720)

---
 CHANGELOG.md | 5 +++++
 Cargo.toml   | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 23357174b..ac5d8d5ce 100644
--- a/CHANGELOG.md
+++ b/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
diff --git a/Cargo.toml b/Cargo.toml
index 793582af1..ef44fbb9d 100644
--- a/Cargo.toml
+++ b/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"