Regression after 3.0.8 (3.0.9+): Batch UPDATE requests with null parameters work incorrectly

    public static void main(String... args) throws Throwable {

        var reproduceThisBug = true;

        var url = "jdbc:mariadb://localhost:3306/test?useServerPrepStmts&useBulkStmts=" + reproduceThisBug;

        try (var conn = DriverManager.getConnection(url, "root", "password")) {

            try (var stmt = conn.createStatement()) {

                stmt.executeUpdate("""

                    CREATE TABLE IF NOT EXISTS testtable(

                        username VARCHAR(100) NOT NULL PRIMARY KEY,

                        timeMs BIGINT NULL DEFAULT NULL

                    )

                    """);

            }

            var sql = """

                INSERT INTO testtable(username, timeMs) VALUES(?, ?) ON DUPLICATE KEY

                    UPDATE timeMs = IF(timeMs IS NULL, ?, IF(? IS NULL, timeMs, ?))

                """;

            try (var stmt = conn.prepareStatement(sql)) {

                Long timeMs1 = 2140L;

                setObjects(stmt,

                    "user1", timeMs1,

                    timeMs1, timeMs1, timeMs1

                );

                stmt.addBatch();

                Long timeMs2 = 1000L;

                setObjects(stmt,

                    "user2", timeMs2,

                    timeMs2, timeMs2, timeMs2

                );

                stmt.addBatch();

                stmt.executeBatch();

            }

            try (var stmt = conn.prepareStatement(sql)) {

                Long timeMs1 = 2030L;

                setObjects(stmt,

                    "user1", timeMs1,

                    timeMs1, timeMs1, timeMs1

                );

                stmt.addBatch();

                Long timeMs2 = null;

                setObjects(stmt,

                    "user2", timeMs2,

                    timeMs2, timeMs2, timeMs2

                );

                stmt.addBatch();

                stmt.executeBatch();

            }

        }

    }

    public static void setObjects(PreparedStatement stmt, Object... args) throws SQLException {

        var offset = 0;

        for (Object arg : args) {

            stmt.setObject(++offset, arg);

        }

    }