Returning body w/ >4GB data panics

[crepererum]

Bug Report

Version

master (e1885211495e63d962bc1d00f9be6eeaab2bb901)

Description

This test panics with thread 'codec::prost::tests::encode_big' panicked at 'assertion failed: len <= std::u32::MAX as usize', tonic/src/codec/encode.rs:127:5, but instead the stream should probably return an error:

    #[tokio::test]
    async fn encode_big() {
        let encoder = MockEncoder::default();

        let msg = vec![0u8; u32::MAX as usize + 1];

        let messages = std::iter::once(Ok::<_, Status>(msg));
        let source = futures_util::stream::iter(messages);

        let body = encode_server(
            encoder,
            source,
            None,
            SingleMessageCompressionOverride::default(),
        );

        futures_util::pin_mut!(body);

        while let Some(r) = body.data().await {
            r.unwrap();
        }
    }