title: Custom validator not called on empty input value referring a two level nested property
body: <p>I have an input text which does not call custom validator when it has two level of nested entities in value.</p>
  
  <pre><code>&lt;p:inputText id="valueField" value="#{bean.obj1.obj2.value}" maxlength="50"&gt;
    &lt;f:validator validatorId="requiredValidator" /&gt;
    &lt;p:ajax event="blur" /&gt;
  &lt;/p:inputText&gt;
  &lt;p:message id="idMsg" for="valueField"/&gt;
  </code></pre>
  
  <p>It works perfectly when I give some value, but whenever I try with an empty value, it does not invoke validator.</p>
  
  <p>And if change the value to <code>#{bean.value}</code> then also it works. </p>