Section::updateAction

public function updateAction($id, array $fields)
{
	$r = $this->checkPermissionIBlockSectionUpdate($id);
	if($r->isSuccess())
	{
		if (isset($fields['IBLOCK_SECTION_ID']) && (int)$fields['IBLOCK_SECTION_ID'] > 0)
		{
			$r = $this->checkPermissionIBlockSectionSectionBindUpdate($fields['IBLOCK_SECTION_ID']);
		}
	}

	if($r->isSuccess())
	{
		$section = new CIBlockSection();

		$r = $this->exists($id);
		if($r->isSuccess())
		{
			$r = $this->updateValidate($fields+['ID'=>$id]);
			if($r->isSuccess())
			{
				$section->Update($id, $fields);
				if($section->LAST_ERROR<>'')
				{
					$r->addError(new Error($section->LAST_ERROR));
				}
			}
		}
	}

	if($r->isSuccess())
	{
		return ['SECTION'=>$this->get($id)];
	}
	else
	{
		$this->addErrors($r->getErrors());
		return null;
	}
}