title: PHP cURL Warning during curl_multi_add_handle
body: <p>My PHP code</p>
  
  <pre><code>    $urlArray = array('http://firsturl.com', 'http://secondurl.com');
      $nodeCount = count($urlArray);
      $chContainter = array();
      $mh = curl_multi_init();
      for($i = 0; $i &lt; $nodeCount; $i++) {
          $chContainter[$i] = curl_init();
          curl_setopt($chContainter[$i], CURLOPT_URL, $urlArray[$i]);
          curl_setopt($chContainter[$i], CURLOPT_HEADER, 0);
          curl_setopt($chContainter[$i], CURLOPT_RETURNTRANSFER,1);
          curl_multi_add_handle($mh,$chContainter[$i]);
      } 
  </code></pre>
  
  <p>is generating the following warning</p>
  
  <blockquote>
    <p>Warning: (null)(): 4 is not a valid
    cURL handle resource in Unknown on
    line 0</p>
    
    <p>Warning: (null)(): 5 is not a valid
    cURL handle resource in Unknown on
    line 0</p>
  </blockquote>
  
  <p>I did some debugging and found out the warning was generated when I try to add curl handle to the $mh.</p>
  
  <p>Please help. Thanks.</p>