8255227: java/net/httpclient/FlowAdapterPublisherTest.java intermittently failing with TestServer: start exception: java.io.IOException: Invalid preface

Backport-of: 0544a73

Author: GoeLin

src/java.net.http/share/classes/jdk/internal/net/http/Stream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -882,7 +882,6 @@ else if (item == COMPLETED) {
                     // handle bytes to send downstream
                     while (item.hasRemaining()) {
                         if (debug.on()) debug.log("trySend: %d", item.remaining());
-                        assert !endStreamSent : "internal error, send data after END_STREAM flag";
                         DataFrame df = getDataFrame(item);
                         if (df == null) {
                             if (debug.on())
@@ -902,9 +901,12 @@ else if (item == COMPLETED) {
                                 connection.resetStream(streamid, ResetFrame.PROTOCOL_ERROR);
                                 throw new IOException(msg);
                             } else if (remainingContentLength == 0) {
+                                assert !endStreamSent : "internal error, send data after END_STREAM flag";
                                 df.setFlag(DataFrame.END_STREAM);
                                 endStreamSent = true;
                             }
+                        } else {
+                            assert !endStreamSent : "internal error, send data after END_STREAM flag";
                         }
                         if (debug.on())
                             debug.log("trySend: sending: %d", df.getDataLength());

test/jdk/java/net/httpclient/http2/server/Http2TestServerConnection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,6 +47,7 @@
 import jdk.internal.net.http.hpack.Encoder;
 import sun.net.www.http.ChunkedInputStream;
 import sun.net.www.http.HttpClient;
+import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static jdk.internal.net.http.frame.SettingsFrame.HEADER_TABLE_SIZE;
 
@@ -304,9 +305,11 @@ void close(int error) {
     private void readPreface() throws IOException {
         int len = clientPreface.length;
         byte[] bytes = new byte[len];
-        is.readNBytes(bytes, 0, len);
+        int n = is.readNBytes(bytes, 0, len);
         if (Arrays.compare(clientPreface, bytes) != 0) {
-            throw new IOException("Invalid preface: " + new String(bytes, 0, len));
+            System.err.printf("Invalid preface: read %d/%d bytes%n", n, len);
+            throw new IOException("Invalid preface: " +
+                    new String(bytes, 0, len, ISO_8859_1));
         }
     }