title: Retrieving all FDF fields crashes server
body: <p>I want to retrieve all fields from a fdf file, which i generated with pdftk. Unfortunately the example provided on the php website makes apache crash...</p>
  
  <p>I have this:</p>
  
  <pre><code>$infdf = fdf_open($fdf_file);
  for ($field = fdf_next_field_name($infdf); $field != ""; $field = fdf_next_field_name($infdf, $field))
  {
      echo "field: $field\n";
  }
  fdf_close($infdf);
  </code></pre>
  
  <p>Any suggestions for the cause of the crash?</p>
  
  <p>Thanks!</p>