Fix #855

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://book.async.rs/overview
 
 ## [Unreleased]
 
+## Fixed
+
+- Ensure `UnixStream::into_raw_fd` doesn't close the file descriptor ([#855](https://github.com/async-rs/async-std/issues/855))
+
 # [1.6.3] - 2020-07-31
 
 ## Added

src/os/unix/net/stream.rs

@@ -252,6 +252,6 @@ impl FromRawFd for UnixStream {
 
 impl IntoRawFd for UnixStream {
     fn into_raw_fd(self) -> RawFd {
-        self.as_raw_fd()
+        (*self.watcher).get_ref().try_clone().unwrap().into_raw_fd()
     }
 }

tests/uds.rs

@@ -29,7 +29,7 @@ fn send_recv() -> io::Result<()> {
 }
 
 #[test]
-fn into_raw_fd() -> io::Result<()> {
+fn into_raw_fd_datagram() -> io::Result<()> {
     use async_std::os::unix::io::{FromRawFd, IntoRawFd};
     task::block_on(async {
         let (socket1, socket2) = UnixDatagram::pair().unwrap();
@@ -45,6 +45,23 @@ fn into_raw_fd() -> io::Result<()> {
     })
 }
 
+#[test]
+fn into_raw_fd_stream() -> io::Result<()> {
+    use async_std::os::unix::io::{FromRawFd, IntoRawFd};
+    task::block_on(async {
+        let (mut socket1, socket2) = UnixStream::pair().unwrap();
+        socket1.write(JULIUS_CAESAR).await?;
+
+        let mut buf = vec![0; 1024];
+
+        let mut socket2 = unsafe { UnixStream::from_raw_fd(socket2.into_raw_fd()) };
+        let n = socket2.read(&mut buf).await?;
+        assert_eq!(&buf[..n], JULIUS_CAESAR);
+
+        Ok(())
+    })
+}
+
 const PING: &[u8] = b"ping";
 const PONG: &[u8] = b"pong";
 const TEST_TIMEOUT: Duration = Duration::from_secs(3);