Issue #10135 - fix empty binary frame from websocket flush

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-websocket/websocket-core-common/src/main/java/org/eclipse/jetty/websocket/core/internal/FragmentExtension.java

@@ -101,7 +101,7 @@ public class FragmentExtension extends AbstractExtension implements DemandChain
         {
             if (first)
             {
-                if (OpCode.isControlFrame(frame.getOpCode()))
+                if (frame.isControlFrame())
                 {
                     emitFrame(frame, callback);
                     return true;

jetty-websocket/websocket-core-common/src/main/java/org/eclipse/jetty/websocket/core/internal/FrameFlusher.java

@@ -43,7 +43,15 @@ import org.slf4j.LoggerFactory;
 
 public class FrameFlusher extends IteratingCallback
 {
-    public static final Frame FLUSH_FRAME = new Frame(OpCode.BINARY);
+    public static final Frame FLUSH_FRAME = new Frame(OpCode.UNDEFINED)
+    {
+        @Override
+        public boolean isControlFrame()
+        {
+            return true;
+        }
+    };
+
     private static final Logger LOG = LoggerFactory.getLogger(FrameFlusher.class);
     private static final Throwable CLOSED_CHANNEL = new StaticException("Closed");
 

jetty-websocket/websocket-core-common/src/main/java/org/eclipse/jetty/websocket/core/internal/PerMessageDeflateExtension.java

@@ -268,7 +268,7 @@ public class PerMessageDeflateExtension extends AbstractExtension implements Dem
         @Override
         protected boolean onFrame(Frame frame, Callback callback, boolean batch)
         {
-            if (OpCode.isControlFrame(frame.getOpCode()))
+            if (frame.isControlFrame())
             {
                 nextOutgoingFrame(frame, callback, batch);
                 return true;
@@ -373,7 +373,7 @@ public class PerMessageDeflateExtension extends AbstractExtension implements Dem
         {
             if (first)
             {
-                if (OpCode.isControlFrame(frame.getOpCode()))
+                if (frame.isControlFrame())
                 {
                     emitFrame(frame, callback);
                     return true;

jetty-websocket/websocket-javax-tests/src/test/java/org/eclipse/jetty/websocket/javax/tests/FlushFrameTest.java

@@ -0,0 +1,184 @@
+//
+// ========================================================================
+// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
+package org.eclipse.jetty.websocket.javax.tests;
+
+import java.net.URI;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import javax.websocket.EndpointConfig;
+import javax.websocket.Session;
+import javax.websocket.server.ServerEndpoint;
+
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.util.BlockingArrayQueue;
+import org.eclipse.jetty.util.Callback;
+import org.eclipse.jetty.websocket.core.CloseStatus;
+import org.eclipse.jetty.websocket.core.CoreSession;
+import org.eclipse.jetty.websocket.core.Frame;
+import org.eclipse.jetty.websocket.core.FrameHandler;
+import org.eclipse.jetty.websocket.core.OpCode;
+import org.eclipse.jetty.websocket.core.client.CoreClientUpgradeRequest;
+import org.eclipse.jetty.websocket.core.client.WebSocketCoreClient;
+import org.eclipse.jetty.websocket.javax.server.config.JavaxWebSocketServletContainerInitializer;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.eclipse.jetty.websocket.core.CloseStatus.NORMAL;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class FlushFrameTest
+{
+    private Server _server;
+    private ServerConnector _connector;
+    private WebSocketCoreClient _client;
+
+    @BeforeEach
+    public void before() throws Exception
+    {
+        _server = new Server();
+        _connector = new ServerConnector(_server);
+        _server.addConnector(_connector);
+
+        ServletContextHandler contextHandler = new ServletContextHandler();
+        JavaxWebSocketServletContainerInitializer.configure(contextHandler, (context, container) ->
+        {
+            container.addEndpoint(WebSocketServerEndpoint.class);
+        });
+        _server.setHandler(contextHandler);
+        _server.start();
+
+        _client = new WebSocketCoreClient();
+        _client.start();
+    }
+
+    @AfterEach
+    public void after() throws Exception
+    {
+        _client.stop();
+        _server.stop();
+    }
+
+    @ServerEndpoint("/")
+    public static class WebSocketServerEndpoint extends EventSocket
+    {
+        @Override
+        public void onOpen(Session session, EndpointConfig endpointConfig)
+        {
+            super.onOpen(session, endpointConfig);
+
+            try
+            {
+                session.getBasicRemote().setBatchingAllowed(true);
+                session.getBasicRemote().flushBatch();
+            }
+            catch (Exception e)
+            {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    @Test
+    public void testFlushWithPermessageDeflate() throws Exception
+    {
+        URI uri = URI.create("ws://localhost:" + _connector.getLocalPort());
+        TestFrameHandler testFrameHandler = new TestFrameHandler();
+        CoreClientUpgradeRequest upgradeRequest = CoreClientUpgradeRequest.from(_client, uri, testFrameHandler);
+        upgradeRequest.addExtensions("permessage-deflate");
+
+        // Once WebSocket connection is opened the server does a flush.
+        CoreSession coreSession = _client.connect(upgradeRequest).get(5, TimeUnit.SECONDS);
+        coreSession.close(NORMAL, null, Callback.NOOP);
+
+        // Receive the close frame and succeed the callback.
+        TestFrameHandler.FrameCallback received = testFrameHandler.received.poll(5, TimeUnit.SECONDS);
+        assertNotNull(received);
+        assertThat(received.frame.getOpCode(), equalTo(OpCode.CLOSE));
+        received.callback.succeeded();
+
+        // FrameHandler is closed normally.
+        assertTrue(testFrameHandler.closeLatch.await(5, TimeUnit.SECONDS));
+        assertNull(testFrameHandler.error);
+        assertThat(testFrameHandler.closeStatus.getCode(), equalTo(NORMAL));
+
+        // We received no other frames.
+        assertTrue(testFrameHandler.received.isEmpty());
+    }
+
+    public static class TestFrameHandler implements FrameHandler
+    {
+        CoreSession coreSession;
+        Throwable error;
+        CloseStatus closeStatus;
+        CountDownLatch openLatch = new CountDownLatch(1);
+        CountDownLatch closeLatch = new CountDownLatch(1);
+        BlockingArrayQueue<FrameCallback> received = new BlockingArrayQueue<>();
+
+        public static class FrameCallback
+        {
+            public FrameCallback(Frame frame, Callback callback)
+            {
+                this.frame = frame;
+                this.callback = callback;
+            }
+
+            public Frame frame;
+            public Callback callback;
+        }
+
+        @Override
+        public void onOpen(CoreSession coreSession, Callback callback)
+        {
+            this.coreSession = coreSession;
+            callback.succeeded();
+            coreSession.demand(1);
+            openLatch.countDown();
+        }
+
+        @Override
+        public void onFrame(Frame frame, Callback callback)
+        {
+            received.offer(new FrameCallback(frame, callback));
+            coreSession.demand(1);
+        }
+
+        @Override
+        public void onError(Throwable cause, Callback callback)
+        {
+            this.error = cause;
+            callback.succeeded();
+        }
+
+        @Override
+        public void onClosed(CloseStatus closeStatus, Callback callback)
+        {
+            this.closeStatus = closeStatus;
+            callback.succeeded();
+            closeLatch.countDown();
+        }
+
+        @Override
+        public boolean isDemanding()
+        {
+            return true;
+        }
+    }
+}