Potential bug with ByteStream's implementation of futures_core::stream::Stream

[Velfi]

The implementation of futures::core::streamforByteStreamis potentially bugged. We've never hit this bug because we only ever parameterizeByteStreams on SdkBodywhich emits all its data in a single chunk. If we used a different type that emitted data in chunks,ByteStream` would perform incomplete reads of data. This is because we're only reading one chunk when we should be reading all remaining data.

impl<B> futures_core::stream::Stream for Inner<B>
where
    B: http_body::Body,
{
    type Item = Result<Bytes, B::Error>;

    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
        match self.project().body.poll_data(cx) {
            Poll::Ready(Some(Ok(mut data))) => {
                let len = data.chunk().len();
                let bytes = data.copy_to_bytes(len);
                Poll::Ready(Some(Ok(bytes)))
            }
            Poll::Ready(None) => Poll::Ready(None),
            Poll::Ready(Some(Err(e))) => Poll::Ready(Some(Err(e))),
            Poll::Pending => Poll::Pending,
        }
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let size_hint = http_body::Body::size_hint(&self.body);
        (
            size_hint.lower() as usize,
            size_hint.upper().map(|u| u as usize),
        )
    }
}