title: can't combine [autofocus="autofocus"] with :input
body: <p>I want to build a query that finds elements that have the autofocus-attribute and are also inputs(or selects).</p>
  
  <p>using this Skeleton....</p>
  
  <pre><code>&lt;html&gt;&lt;head&gt;
     &lt;script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;div id="maindiv"&gt;
          &lt;form class="someclass"&gt;
              &lt;input type="text" /&gt;
              &lt;input type="text" autofocus="autofocus" /&gt;
          &lt;/form&gt;
      &lt;/div&gt;
  &lt;/body&gt;&lt;/html&gt;
  </code></pre>
  
  <p>... i try</p>
  
  <pre><code>$('#maindiv .someclass [autofocus="autofocus"]')
  </code></pre>
  
  <p>Which returns one input, as expected</p>
  
  <pre><code>$('#maindiv .someclass :input')
  </code></pre>
  
  <p>Returns both inputs.</p>
  
  <p>But combining the two always results in an empty list.</p>
  
  <pre><code>$('#maindiv .someclass [autofocus="autofocus"]:input')
  $('#maindiv .someclass :input[autofocus="autofocus"]')
  $('#maindiv .someclass :input').filter('[autofocus="autofocus"]')
  </code></pre>
  
  <p>This one</p>
  
  <pre><code>$('#maindiv .someclass [autofocus="autofocus"]').filter(':input')
  </code></pre>
  
  <p>works and returns one input.</p>
  
  <p>Why is this? </p>