PostFiles::checkAbsolutePath

static function checkAbsolutePath($filePath)
{
	$isCheckedSuccess = false;
	$io = \CBXVirtualIo::GetInstance();
	$docRoot = Application::getDocumentRoot();
	if(mb_strpos($filePath, \CTempFile::GetAbsoluteRoot()) === 0)
	{
		$absPath = $filePath;
	}
	elseif(mb_strpos($io->CombinePath($docRoot, $filePath), \CTempFile::GetAbsoluteRoot()) === 0)
	{
		$absPath = $io->CombinePath($docRoot, $filePath);
	}
	else
	{
		$absPath = $io->CombinePath(\CTempFile::GetAbsoluteRoot(), $filePath);
		$isCheckedSuccess = true;
	}

	$absPath = realpath(str_replace("\\", "/", $absPath));
	if (mb_strpos($absPath, realpath(\CTempFile::GetAbsoluteRoot())) !== 0)
	{
		return null;
	}

	if (!$isCheckedSuccess && $io->ValidatePathString($absPath) && $io->FileExists($absPath))
	{
		$docRoot = $io->CombinePath($docRoot, '/');
		$relPath = str_replace($docRoot, '', $absPath);
		$perm = $GLOBALS['APPLICATION']->GetFileAccessPermission($relPath);
		if ($perm >= "W")
		{
			$isCheckedSuccess = true;
		}
	}

	return [
		'isSuccess' => $isCheckedSuccess,
		'absPath'   => $absPath
	];
}