Regression on ChronicleQueue https://github.com/OpenHFT/Chronicle-Queue/issues/401

output

testRandom fails since 4.6.25 including 4.6.41, output:
75071733366784: msg0
75071733366785: msg1
75071733366786: msg2
75071733366787: msg3
75071733366788: msg4
75071733366789: msg5
75071733366790: msg6
75071733366791: msg7
75071733366792: msg8
75071733366793: msg9
----------
75071733366785: msg1
75071733366786: msg2 next
75071733366786: msg3

org.junit.ComparisonFailure: 
Expected :msg2
Actual   :msg3

testSimple fails since CQ 4.6.25, this is a duplicate as Chronicle-Queue/issues/393 and is fixed in 4.6.38
org.junit.ComparisonFailure: 
Expected :msg2
Actual   :msg4
	at org.nuxeo.lib.stream.tests.TestLibChronicleRegression.testSimple(TestLibChronicleRegression.java:85)

TestLibChronicleRegression.java

/*
 * (C) Copyright 2017 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Contributors:
 *     bdelbosc
 */
package org.nuxeo.lib.stream.tests;


import static org.junit.Assert.assertEquals;
import java.io.File;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

import net.openhft.chronicle.queue.ChronicleQueue;
import net.openhft.chronicle.queue.ExcerptAppender;
import net.openhft.chronicle.queue.ExcerptTailer;
import net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder;

/**
 * Unit Test to learn the Chronicle Queue lib.
 *
 * @since 9.3
 */
public class TestLibChronicleRegression {

    @Rule
    public TemporaryFolder folder = new TemporaryFolder();

    @Test
    public void testSimple() throws Exception {
        File cqFolder = folder.newFolder("cq");
        try (ChronicleQueue queue = SingleChronicleQueueBuilder.binary(cqFolder).build()) {
            // create a queue and add some excerpts
            ExcerptAppender app = queue.acquireAppender();
            for (int i =0; i< 10; i++) {
                final String msg = "msg" + i;
                app.writeDocument(w -> w.write("message").object(msg));
            }
            ExcerptTailer tailer = queue.createTailer().toStart();
            final String[] ret = new String[1];

            // read a msg
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg0", ret[0]);

            // read another one
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg1", ret[0]);

            long pos2 = tailer.index();
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg2", ret[0]);
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg3", ret[0]);


            // go back to pos2
            tailer.moveToIndex(pos2);
            // read a third doc
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg2", ret[0]);
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg3", ret[0]);

            // again
            tailer.moveToIndex(pos2);
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());

            // this return msg4 with chronicle queue 190a05c
            assertEquals("msg2", ret[0]);
            tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
            assertEquals("msg3", ret[0]);

        }
    }

}

TestLibChronicleRegressionBis.java

   @Test
    public void testRandomMove() throws Exception {
        int nbMessages = 10;
        int nbTests = 100;

        Map<Long, String> messages = new HashMap<>(nbMessages);

        File cqFolder = folder.newFolder("cq");
        try (ChronicleQueue queue = SingleChronicleQueueBuilder.binary(cqFolder).build()) {
            // create a queue and add some excerpts
            ExcerptAppender app = queue.acquireAppender();
            for (int i =0; i < nbMessages; i++) {
                final String message = "msg" + i;
                app.writeDocument(w -> w.write("message").object(message));
                if (i < nbMessages + 1) {
                    messages.put(app.lastIndexAppended(), message);
                    System.out.println(app.lastIndexAppended() + ": " + message);
                }
            }
            System.out.println("----------");
            Random random    = new Random();
            List<Long> offsets = new ArrayList<>(messages.keySet());
            ExcerptTailer tailer = queue.createTailer().toStart();
            String[] ret = new String[1];
            for (int i=0; i < nbTests; i++) {
                long offset = offsets.get(random.nextInt(messages.keySet().size()));
                tailer.moveToIndex(offset);
                tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
                System.out.println(offset + ": " + ret[0]);
                assertEquals(messages.get(offset), ret[0]);
                long index = tailer.index();
                tailer.readDocument(w -> ret[0] = (String) w.read("message").object());
                System.out.println(index + ": " + ret[0] + " next");
            }
        }
    }