title: PHP DomXPath not selecting empty text nodes
body: <p>I'm trying to select nodes which don't contain any text.  This bit of php code skips the empty node in the sample xml.  However, when I try an online tester (like <a href="http://freeformatter.com/xpath-tester.html" rel="nofollow">http://freeformatter.com/xpath-tester.html</a>) it doesn't have any problem.</p>
  
  <p>Is this a PHP thing?</p>
  
  <p>My php code:</p>
  
  <pre><code>    $path = "//RecipeSteps/RecipeStep[not(text())]";
      $stepsQuery = $this-&gt;xpath-&gt;query($path);
      $numResults = $stepsQuery-&gt;length;
  </code></pre>
  
  <p>My sample xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;Recipes&gt;
      &lt;RecipeSteps&gt;
        &lt;RecipeStep number="1"&gt;Dummy content&lt;/RecipeStep&gt;
        &lt;RecipeStep number="2"&gt;Dummy content&lt;/RecipeStep&gt;
        &lt;RecipeStep number="3"&gt;Dummy content&lt;/RecipeStep&gt;
        &lt;RecipeStep number="4"&gt;Dummy content&lt;/RecipeStep&gt;
        &lt;RecipeStep number="5"&gt;Dummy content&lt;/RecipeStep&gt;
        &lt;RecipeStep number="6"&gt;&lt;/RecipeStep&gt;
        &lt;RecipeStep number="7"&gt;Variations&lt;/RecipeStep&gt;
        &lt;RecipeStep number="8"&gt;Some variation content..&lt;/RecipeStep&gt;
      &lt;/RecipeSteps&gt;
  &lt;/Recipes&gt;
  </code></pre>