recv_reset resets closed streams with queued EOS frames (#247)

tests/stream_states.rs

@@ -808,3 +808,65 @@ fn send_data_after_headers_eos() {
 fn exceed_max_streams() {
 }
 */
+
+
+#[test]
+fn rst_while_closing() {
+    // Test to reproduce panic in issue #246 --- receipt of a RST_STREAM frame
+    // on a stream in the Half Closed (remote) state with a queued EOS causes
+    // a panic.
+    let _ = ::env_logger::try_init();
+    let (io, srv) = mock::new();
+
+    let srv = srv.assert_client_handshake()
+        .unwrap()
+        .recv_settings()
+        .recv_frame(
+            frames::headers(1)
+                .request("GET", "https://example.com/")
+        )
+        .send_frame(frames::headers(1).response(200))
+        .send_frame(frames::headers(1).eos())
+        // Idling for a moment here is necessary to ensure that the client
+        // enqueues its TRAILERS frame *before* we send the RST_STREAM frame
+        // which causes the panic.
+        .idle_ms(1)
+        // Send the RST_STREAM frame which causes the client to panic.
+        .send_frame(frames::reset(1).cancel())
+        .ping_pong([1; 8])
+        .close();
+        ;
+
+    let client = client::handshake(io)
+        .expect("handshake")
+        .and_then(|(mut client, conn)| {
+            let request = Request::builder()
+                .method(Method::GET)
+                .uri("https://example.com/")
+                .body(())
+                .unwrap();
+
+            // The request should be left streaming.
+            let (resp, mut stream) = client.send_request(request, false)
+                .expect("send_request");
+            let req = resp
+                // on receipt of an EOS response from the server, transition
+                // the stream Open => Half Closed (remote).
+                .expect("response")
+                .and_then(move |resp| {
+                    assert_eq!(resp.status(), StatusCode::OK);
+                    // Enqueue trailers frame.
+                    let _ = stream.send_trailers(HeaderMap::new());
+                    Ok(())
+                })
+                .map_err(|()| -> Error {
+                    unreachable!()
+                });
+
+            conn.drive(req)
+                .and_then(|(conn, _)| conn.expect("client"))
+        });
+
+
+    client.join(srv).wait().expect("wait");
+}