Fixed a bug with the channels.

src/lib.rs

@@ -671,6 +671,22 @@ impl<T: Unpin> Sender<T> {
 	}
 }
 
+impl<T> Drop for Sender<T> {
+	#[inline]
+	fn drop(&mut self) {
+		// check if there are still receivers
+		if let Some(chan) = self.0.upgrade() {
+			// check if we're the last sender to drop
+			if Rc::weak_count(&chan) == 1 {
+				// awake all of the waiting receivers so that they get to return
+				for process in chan.borrow_mut().waiting.drain(..) {
+					process.wake();
+				}
+			}
+		}
+	}
+}
+
 impl<T: Unpin> Receiver<T> {
 	/// Returns a future that can be awaited to receive a message.
 	pub fn recv(&self) -> ReceiveFuture<T> {