From ed4ddf443d93c3e14ae23699a5a2f81902ad1e66 Mon Sep 17 00:00:00 2001
From: Eric Seppanen <109770420+eric-seppanen@users.noreply.github.com>
Date: Fri, 21 Jun 2024 06:00:33 -0700
Subject: [PATCH] io: fix trait bounds on impl Sink for StreamReader (#6647)

This impl had a bound on `StreamReader<S, E>`; this is incorrect
because:
- The second generic parameter to `StreamReader` is not an error type;
  it's a buffer type.
- The `Stream` error type in `StreamReader` should not need to be the
  same as the `Sink` error type.

This "passthrough" `Sink` impl was effectively unusable because it
required the `Sink` error type be the same as the `StreamReader` buffer
type.

Resolve this by allowing the `StreamReader` buffer to be anything in
this impl.
---
 tokio-util/src/io/stream_reader.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tokio-util/src/io/stream_reader.rs b/tokio-util/src/io/stream_reader.rs
index 096c96f30..7569a8b78 100644
--- a/tokio-util/src/io/stream_reader.rs
+++ b/tokio-util/src/io/stream_reader.rs
@@ -326,7 +326,7 @@ impl<S, B> StreamReader<S, B> {
     }
 }
 
-impl<S: Sink<T, Error = E>, E, T> Sink<T> for StreamReader<S, E> {
+impl<S: Sink<T, Error = E>, B, E, T> Sink<T> for StreamReader<S, B> {
     type Error = E;
     fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         self.project().inner.poll_ready(cx)