Notice: Use of undefined constant headers_list - assumed 'headers_list' in boost_headers_contain() (line 2640 of boost.module

Fix: (patch)

function boost_headers_contain($text) {
-  if (function_exists(headers_list)) {
+  if (function_exists('headers_list')) {
    $list = headers_list();
    if (empty($list)) {
      return FALSE;
    }
    foreach ($list as $header) {
      $info = stristr($header, $text);
      if ($info !== FALSE) {
        return $info;
      }
    }
  }
  return FALSE;
}