title: Type of "application/json" prevents post variables from being sent
body: <p>I've found that if I try a PHP POST curl, the postvars are sent fine. Once I add the httpheader of content-type: <code>application/json</code> the postvars don't go across any more. I've tried the postvars as a JSON string and as a query string.</p>
  
  <p>Showing some code:</p>
  
  <pre><code>$ch = curl_init();
  
  $post =  json_encode(array('p1' =&gt; 'blahblahblah', 'p2' =&gt; json_encode(array(4,5,6))));
  
  $arr = array();
  array_push($arr, 'Content-Type: application/json; charset=utf-8');
  
  curl_setopt($ch, CURLOPT_HTTPHEADER, $arr);
  curl_setopt($ch, CURLOPT_URL, 'https://example.com/file.php');
  curl_setopt($ch, CURLOPT_POST, true);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
  
  curl_exec($ch);
  curl_close($ch);
  </code></pre>