Support STOMP DISCONNECT with receipt

Issue: SPR-11599

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompBrokerRelayMessageHandler.java

@@ -759,7 +759,7 @@ public class StompBrokerRelayMessageHandler extends AbstractBrokerMessageHandler
 				@Override
 				public void onSuccess(Void result) {
 					if (accessor.getCommand() == StompCommand.DISCONNECT) {
-						clearConnection();
+						afterDisconnectSent(accessor);
 					}
 				}
 				@Override
@@ -775,6 +775,21 @@ public class StompBrokerRelayMessageHandler extends AbstractBrokerMessageHandler
 			return future;
 		}
 
+		/**
+		 * After a DISCONNECT there should be no more client frames so we can
+		 * close the connection pro-actively. However, if the DISCONNECT has a
+		 * receipt header we leave the connection open and expect the server will
+		 * respond with a RECEIPT and then close the connection.
+		 *
+		 * @see <a href="http://stomp.github.io/stomp-specification-1.2.html#DISCONNECT">
+		 *     STOMP Specification 1.2 DISCONNECT</a>
+		 */
+		private void afterDisconnectSent(StompHeaderAccessor accessor) {
+			if (accessor.getReceipt() == null) {
+				clearConnection();
+			}
+		}
+
 		/**
 		 * Clean up state associated with the connection and close it.
 		 * Any exception arising from closing the connection are propagated.

spring-messaging/src/test/java/org/springframework/messaging/simp/stomp/StompBrokerRelayMessageHandlerIntegrationTests.java

@@ -223,11 +223,6 @@ public class StompBrokerRelayMessageHandlerIntegrationTests {
 
 		startActiveMqBroker();
 		this.eventPublisher.expectBrokerAvailabilityEvent(true);
-
-		// TODO The event publisher assertions show that the broker's back up and the system relay session
-		// has reconnected. We need to decide what we want the reconnect behaviour to be for client relay
-		// sessions and add further message sending and assertions as appropriate. At the moment any client
-		// sessions will be closed and an ERROR from will be sent.
 	}
 
 	@Test
@@ -249,6 +244,21 @@ public class StompBrokerRelayMessageHandlerIntegrationTests {
 		assertTrue("Unexpected messages: " + this.responseHandler.queue, this.responseHandler.queue.isEmpty());
 	}
 
+	@Test
+	public void disconnectWithReceipt() throws Exception {
+
+		logger.debug("Starting test disconnectWithReceipt()");
+
+		MessageExchange connect = MessageExchangeBuilder.connect("sess1").build();
+		this.relay.handleMessage(connect.message);
+		this.responseHandler.expectMessages(connect);
+
+		MessageExchange disconnect = MessageExchangeBuilder.disconnectWithReceipt("sess1", "r123").build();
+		this.relay.handleMessage(disconnect.message);
+
+		this.responseHandler.expectMessages(disconnect);
+	}
+
 
 	private static class TestEventPublisher implements ApplicationEventPublisher {
 
@@ -403,6 +413,18 @@ public class StompBrokerRelayMessageHandlerIntegrationTests {
 			return new MessageExchangeBuilder(message);
 		}
 
+		public static MessageExchangeBuilder disconnectWithReceipt(String sessionId, String receiptId) {
+
+			StompHeaderAccessor headers = StompHeaderAccessor.create(StompCommand.DISCONNECT);
+			headers.setSessionId(sessionId);
+			headers.setReceipt(receiptId);
+			Message<?> message = MessageBuilder.createMessage(new byte[0], headers.getMessageHeaders());
+
+			MessageExchangeBuilder builder = new MessageExchangeBuilder(message);
+			builder.expected.add(new StompReceiptFrameMessageMatcher(sessionId, receiptId));
+			return builder;
+		}
+
 		public MessageExchangeBuilder andExpectMessage(String sessionId, String subscriptionId) {
 			Assert.isTrue(SimpMessageType.MESSAGE.equals(headers.getMessageType()));
 			String destination = this.headers.getDestination();