diff --git a/tokio/src/io/util/write_int.rs b/tokio/src/io/util/write_int.rs index 28add549971812b0ff0531cc66928d790be112ef..672c35f076892592331ecb06ff1f0ae2c2d41e13 100644 --- a/tokio/src/io/util/write_int.rs +++ b/tokio/src/io/util/write_int.rs @@ -56,6 +56,9 @@ macro_rules! writer { { Poll::Pending => return Poll::Pending, Poll::Ready(Err(e)) => return Poll::Ready(Err(e.into())), + Poll::Ready(Ok(0)) => { + return Poll::Ready(Err(io::ErrorKind::WriteZero.into())); + } Poll::Ready(Ok(n)) => n as u8, }; } @@ -96,7 +99,7 @@ macro_rules! writer8 { match me.dst.poll_write(cx, &buf[..]) { Poll::Pending => Poll::Pending, Poll::Ready(Err(e)) => Poll::Ready(Err(e.into())), - Poll::Ready(Ok(0)) => Poll::Pending, + Poll::Ready(Ok(0)) => Poll::Ready(Err(io::ErrorKind::WriteZero.into())), Poll::Ready(Ok(1)) => Poll::Ready(Ok(())), Poll::Ready(Ok(_)) => unreachable!(), } diff --git a/tokio/tests/io_write_int.rs b/tokio/tests/io_write_int.rs new file mode 100644 index 0000000000000000000000000000000000000000..48a583d8c3f32d8611881bffa9eb9e0c92a4d714 --- /dev/null +++ b/tokio/tests/io_write_int.rs @@ -0,0 +1,37 @@ +#![warn(rust_2018_idioms)] +#![cfg(feature = "full")] + +use tokio::io::{AsyncWrite, AsyncWriteExt}; + +use std::io; +use std::pin::Pin; +use std::task::{Context, Poll}; + +#[tokio::test] +async fn write_int_should_err_if_write_count_0() { + struct Wr {} + + impl AsyncWrite for Wr { + fn poll_write( + self: Pin<&mut Self>, + _cx: &mut Context<'_>, + _buf: &[u8], + ) -> Poll<io::Result<usize>> { + Ok(0).into() + } + + fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> { + Ok(()).into() + } + + fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> { + Ok(()).into() + } + } + + let mut wr = Wr {}; + + // should be ok just to test these 2, other cases actually expanded by same macro. + assert!(wr.write_i8(0).await.is_err()); + assert!(wr.write_i32(12).await.is_err()); +}