Ensures chunked encoding is enabled whenever there are trailers to be…

… sent, even if a Content-Length header was specified. New test that adds a trailer and sets a Content-Length header. (helidon-io#9334)

webserver/tests/webserver/src/test/java/io/helidon/webserver/tests/HeadersServerTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023 Oracle and/or its affiliates.
+ * Copyright (c) 2023, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -89,6 +89,16 @@ static void router(HttpRouting.Builder router) {
                          res.send(DATA);
                      }
         );
+        router.route(GET, "/stream-with-trailers-and-length",
+                     (req, res) -> {
+                         res.header(HeaderNames.TRAILER, TEST_TRAILER_HEADER.name());
+                         res.header(HeaderNames.CONTENT_LENGTH, String.valueOf(DATA.length()));     // must switch to chunked
+                         try (var os = res.outputStream()) {
+                             os.write(DATA.getBytes());
+                         }
+                         res.trailers().add(TEST_TRAILER_HEADER);
+                     }
+        );
     }
 
     @Test
@@ -149,6 +159,19 @@ void trailersNoTrailers(WebClient client) {
                         + "response headers have trailer names definition 'Trailer: <trailer-name>'"));
     }
 
+    @Test
+    void streamWithTrailersAndLength(WebClient client) throws IOException {
+        ClientResponseTyped<InputStream> res = client
+                .get("/stream-with-trailers-and-length")
+                .header(HeaderValues.TE_TRAILERS)
+                .request(InputStream.class);
+        assertThat(res.headers(), hasHeader(HeaderValues.TRANSFER_ENCODING_CHUNKED));       // trailers need chunked
+        try (var ins = res.entity()) {
+            assertThat(ins.readAllBytes(), is(DATA.getBytes()));
+        }
+        assertThat(res.trailers(), hasHeader(TEST_TRAILER_HEADER));
+    }
+
     private void checkCachedConnection(ClientResponseHeaders h) {
         if (clientPort == -1) {
             clientPort = h.get(CLIENT_PORT_HEADER_NAME).asInt().get();

webserver/webserver/src/main/java/io/helidon/webserver/http1/Http1ServerResponse.java

@@ -479,10 +479,15 @@ private BlockingOutputStream(ServerResponseHeaders headers,
             this.validateHeaders = validateHeaders;
         }
 
-        void checkResponseHeaders(){
-            this.isChunked = !headers.contains(HeaderNames.CONTENT_LENGTH);
-            this.forcedChunked = headers.contains(HeaderValues.TRANSFER_ENCODING_CHUNKED)
-                    || headers.contains(HeaderNames.TRAILER);
+        void checkResponseHeaders() {
+            if (headers.contains(HeaderNames.TRAILER)) {
+                headers.remove(HeaderNames.CONTENT_LENGTH);
+                isChunked = true;
+                forcedChunked = true;
+            } else {
+                isChunked = !headers.contains(HeaderNames.CONTENT_LENGTH);
+                forcedChunked = headers.contains(HeaderValues.TRANSFER_ENCODING_CHUNKED);
+            }
         }
 
         @Override
@@ -557,13 +562,13 @@ void commit() {
             }
 
             if (sendTrailers) {
-                    // not optimized, trailers enabled: we need to write trailers
-                    trailers.set(STREAM_RESULT_NAME, streamResult.get());
-                    BufferData buffer = BufferData.growing(128);
-                    writeHeaders(trailers, buffer, this.validateHeaders);
-                    buffer.write('\r');        // "\r\n" - empty line after headers
-                    buffer.write('\n');
-                    dataWriter.write(buffer);
+                // not optimized, trailers enabled: we need to write trailers
+                trailers.set(STREAM_RESULT_NAME, streamResult.get());
+                BufferData buffer = BufferData.growing(128);
+                writeHeaders(trailers, buffer, this.validateHeaders);
+                buffer.write('\r');        // "\r\n" - empty line after headers
+                buffer.write('\n');
+                dataWriter.write(buffer);
             }
 
             responseCloseRunnable.run();