TYPO3 Core

AFAICS sorting is done in process_datamap, which is called by process_cmdmap in case of 'copy' but not in case of 'move', since usually there is no data to be processed, when moving a record.

So sorting should be handled at lines 1058 to 1082 of \TYPO3\CMS\Core\DataHandling\DataHandler

// The $pid_value is now the numerical pid at this point
if ($OK) {
    $sortRow = $GLOBALS['TCA'][$table]['ctrl']['sortby'];
    // Points to a page on which to insert the element, possibly in the top of the page
    if ($pid_value >= 0) {
        // If this table is sorted we better find the top sorting number
        if ($sortRow) {
            $fieldArray[$sortRow] = $this->getSortNumber($table, 0, $pid_value);
        }
        // The numerical pid is inserted in the data array
        $fieldArray['pid'] = $pid_value;
    } else {
        // points to another record before ifself
        // If this table is sorted we better find the top sorting number
        if ($sortRow) {
            // Because $pid_value is < 0, getSortNumber returns an array
            $tempArray = $this->getSortNumber($table, 0, $pid_value);
            $fieldArray['pid'] = $tempArray['pid'];
            $fieldArray[$sortRow] = $tempArray['sortNumber'];
        } else {
            // Here we fetch the PID of the record that we point to...
            $tempdata = $this->recordInfo($table, abs($pid_value), 'pid');
            $fieldArray['pid'] = $tempdata['pid'];
        }
    }
}