title: Sitecore 8 throwing null exception when Datasource item does not exist
body: <p>I am facing the below problem and can't find out how to get around to it.</p>
  <ol>
  <li>I have a rendering and its datasource is pointing to an item in the tree.</li>
  <li>I publish the rendering but I don't publish the referenced item.</li>
  <li>While viewing the page I get an error. [attached is the screen shot of the error i am getting]</li>
  </ol>
  <p><a href="https://i.stack.imgur.com/z3Ra3.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/z3Ra3.jpg" alt="enter image description here" /></a></p>
  <p>I am using glass mapper.</p>
  <p>Thanks in advance for your help.</p>