<!DOCTYPE html>
<html layout:decorate="~{base}">
<head>
  <title
    th:if="${blogDescription}"
    th:text="${blogTitle} + ' &#8211; ' + ${blogDescription}">
      Yule blog engine
  </title>
  <title th:unless="${blogDescription}" th:text="${blogTitle}">
    Yule blog engine 2
  </title>
  </head>
<body>
  <section layout:fragment="content">
    <p>Blog index paragraph</p>
  </section>
</body>
</html>

<!DOCTYPE html>
<html layout:decorate="~{base}">
  <head>
    <title
      th:text="${blogDescription} ? (${blogTitle} + ' - ' + ${blogDescription}): (${blogTitle})">
      Blog title
    </title>
  </head>
<body>
  <section layout:fragment="content">
    <p>Blog index paragraph</p>
  </section>
</body>
</html>

Replace two <title> tags with one
Replace two <title> tags with one

The two tags are being replaced with just one that uses conditional text
content.
