Unsupported operand types in messaging module (fatal error on admin page)

On going to any edit a content type page

http://dev.example.com/admin/content/types/promo-badge

Fatal error: Unsupported operand types in /var/www/vhosts/dev.example.com/httpdocs/sites/all/modules/messaging/messaging.module on line 982

Which is the second-to-last line of this function of the messaging.module:

<?php
/**
 * Helper function for mail methods
 *
 * This is the only non method agnostic functionality in this module. As there are several plug-ins
 * for mail sending, we add this helper function here so its available for all them
 */
function messaging_mail_params($message, $params) {
  // The message 'from' will depend on message sender if present
  if (empty($params['from'])) {
    if (!empty($message['sender_account']) && !empty($message['sender_account']->mail)) {
      $params['from'] = check_plain($message['sender_account']->name) . ' <'.$message['sender_account']->mail.'>';
    } elseif(!empty($message['sender_name']) && ($default_from = variable_get('site_mail', ini_get('sendmail_from')))) {
      $params['from'] = check_plain($message['sender_name']) . ' <'.$default_from.'>';
    }
  }
  // Fill in params with default values if not present
  $params += array('from' => NULL, 'headers' => array(), 'mailkey' => 'message-'.$message['type']);
  return $params;
}
?>

Which looks truly wrong. Can arrays really use the += operator? I think not: http://us.php.net/manual/en/language.operators.assignment.php

Resolution

... and then I realized I didn't end up using the messaging framework yet so I just disabled the module.