Semantics of Receiver::try_recv() differ between Sender and SyncSender

[GGist]

I tried this code:

use std::sync::mpsc::{self};
use std::mem;

fn main() {
    let (sync_send, sync_recv) = mpsc::sync_channel(1);

    sync_send.send(()).unwrap();
    mem::drop(sync_send);

    println!("{:?}", sync_recv.try_recv());

    //-----------------------------------------//

    let (send, recv) = mpsc::channel();

    send.send(()).unwrap();
    mem::drop(send);

    println!("{:?}", recv.try_recv());
}

I expected to see this happen:

Ok(())
Ok(())

Instead, this happened:

Err(Disconnected)
Ok(())

Notes

I see that in the docs there is a comment under the Receiver::recv() method that states "However, since channels are buffered, messages sent before the disconnect will still be properly received." but this comment is not duplicated under Receiver::try_recv().

However, I tried tracing the specific Receiver used in conjunction with SyncSenders which led me to here where it looks like an eager check for a disconnect while ignoring possible data that is still buffered in the Queue. Is this intended?

[alexcrichton]

Oh dear, this definitely looks like a bug to me! If you've got a fix in mind, feel free to send a PR of course!