Response#end should throw ISE if used inside headers end handler

See #4326

This aligns behaviors of Http 1 and Http2 servers.

Signed-off-by: Thomas Segismont <tsegismont@gmail.com>

src/main/java/io/vertx/core/http/impl/Http1xServerResponse.java

@@ -36,8 +36,8 @@
 import io.vertx.core.http.HttpServerResponse;
 import io.vertx.core.http.impl.headers.HeadersMultiMap;
 import io.vertx.core.impl.ContextInternal;
-import io.vertx.core.impl.future.PromiseInternal;
 import io.vertx.core.impl.VertxInternal;
+import io.vertx.core.impl.future.PromiseInternal;
 import io.vertx.core.impl.logging.Logger;
 import io.vertx.core.impl.logging.LoggerFactory;
 import io.vertx.core.net.NetSocket;
@@ -48,10 +48,9 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.RandomAccessFile;
-import java.util.Map;
 import java.util.Set;
 
-import static io.vertx.core.http.HttpHeaders.SET_COOKIE;
+import static io.vertx.core.http.HttpHeaders.*;
 
 /**
  *
@@ -399,6 +398,7 @@ private void end(Buffer chunk, PromiseInternal<Void> listener) {
       if (written) {
         throw new IllegalStateException(RESPONSE_WRITTEN);
       }
+      written = true;
       ByteBuf data = chunk.getByteBuf();
       bytesWritten += data.readableBytes();
       HttpObject msg;
@@ -411,7 +411,6 @@ private void end(Buffer chunk, PromiseInternal<Void> listener) {
         msg = new AssembledLastHttpContent(data, trailingHeaders);
       }
       conn.writeToChannel(msg, listener);
-      written = true;
       conn.responseComplete();
       if (bodyEndHandler != null) {
         bodyEndHandler.handle(null);
@@ -690,6 +689,7 @@ private void checkHeadWritten() {
   }
 
   private void prepareHeaders(long contentLength) {
+    headWritten = true;
     if (version == HttpVersion.HTTP_1_0 && keepAlive) {
       headers.set(HttpHeaders.CONNECTION, HttpHeaders.KEEP_ALIVE);
     } else if (version == HttpVersion.HTTP_1_1 && !keepAlive) {
@@ -717,7 +717,6 @@ private void prepareHeaders(long contentLength) {
       // TODO : DONE SOMEWHERE ELSE FROM EVENT LOOP
       reportResponseBegin();
     }
-    headWritten = true;
   }
 
   private void setCookies() {

src/test/java/io/vertx/core/http/HttpTest.java

@@ -17,14 +17,27 @@
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.netty.handler.codec.http2.Http2Exception;
 import io.vertx.codegen.annotations.Nullable;
+import io.vertx.core.AbstractVerticle;
+import io.vertx.core.AsyncResult;
+import io.vertx.core.Context;
+import io.vertx.core.DeploymentOptions;
 import io.vertx.core.Future;
-import io.vertx.core.*;
+import io.vertx.core.Handler;
+import io.vertx.core.MultiMap;
+import io.vertx.core.Promise;
+import io.vertx.core.Vertx;
+import io.vertx.core.VertxException;
+import io.vertx.core.VertxOptions;
 import io.vertx.core.buffer.Buffer;
 import io.vertx.core.dns.AddressResolverOptions;
 import io.vertx.core.http.impl.HttpServerRequestInternal;
 import io.vertx.core.http.impl.ServerCookie;
 import io.vertx.core.impl.Utils;
-import io.vertx.core.net.*;
+import io.vertx.core.net.NetClient;
+import io.vertx.core.net.NetClientOptions;
+import io.vertx.core.net.NetServerOptions;
+import io.vertx.core.net.NetSocket;
+import io.vertx.core.net.SocketAddress;
 import io.vertx.core.net.impl.HAProxyMessageCompletionHandler;
 import io.vertx.core.streams.Pump;
 import io.vertx.core.streams.ReadStream;
@@ -39,24 +52,49 @@
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
-import java.io.*;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.OutputStreamWriter;
+import java.io.UnsupportedEncodingException;
 import java.net.ServerSocket;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
-import java.util.*;
-import java.util.concurrent.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.TimeZone;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
-import java.util.function.*;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.stream.IntStream;
 
-import static io.vertx.core.http.HttpMethod.PUT;
+import static io.vertx.core.http.HttpMethod.*;
 import static io.vertx.test.core.TestUtils.*;
-import static java.util.Collections.singletonList;
+import static java.util.Collections.*;
 
 /**
  * @author <a href="mailto:julien@julienviet.com">Julien Viet</a>
@@ -6705,4 +6743,31 @@ private void testResponseEndFutureCompletes(final Function<HttpServerResponse, F
       .onComplete(onSuccess(nothing -> complete()));
     await();
   }
+
+  @Test
+  public void shouldThrowISEIfSendingResponseFromHeadersEndHandler() throws Exception {
+    AtomicBoolean flag = new AtomicBoolean();
+    waitFor(3);
+    server.requestHandler(req -> {
+        HttpServerResponse resp = req.response();
+        resp.headersEndHandler(v -> {
+          if (flag.compareAndSet(false, true)) {
+            try {
+              resp.end("bar");
+            } catch (IllegalStateException e) {
+              complete();
+            }
+          }
+        });
+        resp.end("foo");
+        complete();
+      }
+    );
+    startServer(testAddress);
+    client.request(requestOptions)
+      .compose(HttpClientRequest::send)
+      .compose(HttpClientResponse::end)
+      .onComplete(onSuccess(nothing -> complete()));
+    await();
+  }
 }