healerearlysessionstart.php

<?php
 
namespace Bitrix\Main\Session\Legacy;
 
use Bitrix\Main\Session\KernelSessionProxy;
use Bitrix\Main\Session\SessionInterface;
use Bitrix\Main\SystemException;
 
final class HealerEarlySessionStart
{
    public function process(SessionInterface $kernelSession)
    {
        if (($kernelSession instanceof KernelSessionProxy) && $kernelSession->isActive() && !$kernelSession->isStarted())
        {
            session_write_close();
 
            $exception = new SystemException(
                'Attention! The session_start function was called before the Bitrix Kernel was started. ' .
                'The session will be closed to avoid errors. It\'s strongly recommended to avoid session usage before initializing the Bitrix Kernel.'
            );
            trigger_error($exception->getMessage(), E_USER_DEPRECATED);
            $application = \Bitrix\Main\Application::getInstance();
            $exceptionHandler = $application->getExceptionHandler();
            $exceptionHandler->writeToLog($exception);
        }
    }
}