Another add-ons overcomes this. It places a file in the root of your XF called /avatar.php ....
<?php
$startTime = microtime(true);
$fileDir = dirname(__FILE__);
require($fileDir . '/library/XenForo/Autoloader.php');
XenForo_Autoloader::getInstance()->setupAutoloader($fileDir . '/library');
XenForo_Application::initialize($fileDir . '/library', $fileDir);
XenForo_Application::set('page_start_time', $startTime);
####################
// GET DB
$db = XenForo_Application::get('db');
// ASSIGN GET PARAMETERS
$userid = (!empty($_GET['userid']) ? intval($_GET['userid']) : false);
$username = (!empty($_GET['username']) ? $_GET['username'] : false);
$size = (!empty($_GET['size']) ? $_GET['size'] : false);
// ENFORCE VALUES FOR SIZE, AND SET DEFAULT 'm'
$size = (in_array($size, array('s','m','l')) ? $size : 'm');
// GET USER BY USERID
if ($userid)
{
$user = $db->fetchRow("
SELECT *
FROM xf_user
WHERE user_id = ?
", $userid);
}
// ELSE GET USER BY USERNAME
else if ($username)
{
$user = $db->fetchRow("
SELECT *
FROM xf_user
WHERE username = ?
", $username);
}
// USER NOT FOUND, OUTPUT DEFAULT NO GENDER
if (empty($user['user_id']))
{
$file = "./styles/default/xenforo/avatars/avatar_{$size}.png";
$type = 'image/png';
header('Content-Type:'.$type);
header('Content-Length: ' . filesize($file));
readfile($file);
exit(0);
}
// GRAVATARS
if ($user['gravatar'])
{
$avaurl = XenForo_Template_Helper_Core::getAvatarUrl($user, $size);
$file = $avaurl;
$filecontents = file_get_contents($file);
$type = 'image/jpeg';
header('Content-Type:'.$type);
header('Content-Length: ' . strlen($filecontents));
echo $filecontents;
exit(0);
}
// CUSTOM AVATARS
if (!empty($user['avatar_date']))
{
// https://xenforo.com/community/threads/avatar-php.30739/page-2#post-892524
// $avaurl = XenForo_Template_Helper_Core::getAvatarUrl($user, $size, 'custom');
$group = floor($user['user_id'] / 1000);
$avaurl = "data" . "/avatars/$size/$group/$user[user_id].jpg?$user[avatar_date]";
$file = './' . substr($avaurl, 0, strpos($avaurl, '?'));
$type = 'image/jpeg';
header('Content-Type:'.$type);
header('Content-Length: ' . filesize($file));
readfile($file);
exit(0);
}
// DEFAULT AVATARS
if (true)
{
$avaurl = XenForo_Template_Helper_Core::getAvatarUrl($user, $size, 'default');
$file = './' . $avaurl;
$type = 'image/png';
header('Content-Type:'.$type);
header('Content-Length: ' . filesize($file));
readfile($file);
exit(0);
}