title: Null attribute in MVC 5 not rendering. What kind of magic is this?
body: <pre><code>&lt;form name="mailform" id="mailform" method="post" action="@(ViewBag.Test)" class="testForm"&gt;
  </code></pre>
  
  <p>What I thing that this will render my action attribute like <code>action=""</code> (in case of <code>ViewBag.Test = null</code>) but I am confused with ASP.NET MVC's behaviour.</p>
  
  <p>When ViewBag.Test is not defined than my action attribute is not rendering. For confirm I open the View-source in Chrome and Firefox and none of both have action attribute for my form. I also check it by change the text but action attribute is remain not rendering.</p>
  
  <p>Can someone explain what is it? And the link that I can verify it's the common behaviour of ASP.NET MVC 5</p>