title: Cannot delete a cookie with explicit domain when it has been created with default domain
body: <p>I've got a website, let's call it <code>www.example.com</code> In that website there are two pages. One creates a cookie like this:</p>
  
  <pre><code>setcookie('daCookie', 'boo', 2000000000, '/', '', false, true);
  </code></pre>
  
  <p>And the other one tries to delete it like this:</p>
  
  <pre><code>setcookie('daCookie', '', 1, '/', 'www.example.com', false, true);
  setcookie('daCookie', '', 1, '/', '.www.example.com', false, true);
  </code></pre>
  
  <p>Now, I <strong>know</strong> that the first script was called in context of <code>www.example.com</code>. If I use the browser's (Google Chrome in this case) developer tools, I can see that the cookie's domain is <code>www.example.com</code>. However the second call does not delete it. If I change it to the empty domain:</p>
  
  <pre><code>setcookie('daCookie', '', 1, '/', '', false, true);
  </code></pre>
  
  <p>Then it works. But I'd really like to specify the domain explicitly. Why doesn't it work?</p>