Stock/Assigner/StockUnitAssigner.php
protected function resolveSoldDeltaQuantity(SaleItemInterface $item)
    {
        $old = $new = $item->getQuantity();

        // Own item quantity changes
        if ($this->persistenceHelper->isChanged($item, 'quantity')) {
            list($old, $new) = $this->persistenceHelper->getChangeSet($item, 'quantity');
        }

        // Parent items quantity changes
        $parent = $item;
        while (null !== $parent = $parent->getParent()) {
            if ($this->persistenceHelper->isChanged($parent, 'quantity')) {
                list($parentOld, $parentNew) = $this->persistenceHelper->getChangeSet($parent, 'quantity');
            } else {
                $parentOld = $parentNew = $parent->getQuantity();
            }
            $old *= $parentOld;
            $new *= $parentNew;
        }

        // Sale released change
        $sale = $item->getSale();
        $shippedOld = $shippedNew = 0;
        $f = $t = false;
        if ($this->persistenceHelper->isChanged($sale, 'released')) {
            list($f, $t) = $this->persistenceHelper->getChangeSet($sale, 'released');
        } elseif ($item->getSale()->isReleased()) {
            $f = $t = true;
        }
        if ($f || $t) {
            /** @var StockAssignmentsInterface $item */
            foreach ($item->getStockAssignments() as $assignment) {
                if ($this->persistenceHelper->isChanged($assignment, 'shippedQuantity')) {
                    list($o, $n) = $this->persistenceHelper->getChangeSet($assignment, 'shippedQuantity');
                } else {
                    $o = $n = $assignment->getShippedQuantity();
                }
                if ($f) {
                    $shippedOld += $o;
                }
                if ($t) {
                    $shippedNew += $n;
                }
            }

            if ($f) {
                $old = min($old, $shippedOld);
            }
            if ($t) {
                $new = min($new, $shippedNew);
            }
        }

        return $new - $old;
    }
protected function resolveSoldDeltaQuantity(SaleItemInterface $item)
    {
        $old = $new = $item->getQuantity();

        // Own item quantity changes
        if ($this->persistenceHelper->isChanged($item, 'quantity')) {
            list($old, $new) = $this->persistenceHelper->getChangeSet($item, 'quantity');
        }

        // Parent items quantity changes
        $parent = $item;
        while (null !== $parent = $parent->getParent()) {
            if ($this->persistenceHelper->isChanged($parent, 'quantity')) {
                list($parentOld, $parentNew) = $this->persistenceHelper->getChangeSet($parent, 'quantity');
            } else {
                $parentOld = $parentNew = $parent->getQuantity();
            }
            $old *= $parentOld;
            $new *= $parentNew;
        }

        // Sale released change
        $sale = $item->getSale();
        $shippedOld = $shippedNew = 0;
        $f = $t = false;
        if ($this->persistenceHelper->isChanged($sale, 'released')) {
            list($f, $t) = $this->persistenceHelper->getChangeSet($sale, 'released');
        } elseif ($item->getSale()->isReleased()) {
            $f = $t = true;
        }
        if ($f || $t) {
            /** @var StockAssignmentsInterface $item */
            foreach ($item->getStockAssignments() as $assignment) {
                if ($this->persistenceHelper->isChanged($assignment, 'shippedQuantity')) {
                    list($o, $n) = $this->persistenceHelper->getChangeSet($assignment, 'shippedQuantity');
                } else {
                    $o = $n = $assignment->getShippedQuantity();
                }
                if ($f) {
                    $shippedOld += $o;
                }
                if ($t) {
                    $shippedNew += $n;
                }
            }

            if ($f) {
                $old = min($old, $shippedOld);
            }
            if ($t) {
                $new = min($new, $shippedNew);
            }
        }

        return $new - $old;
    }
Resolves the assignments update's delta quantity.

@param SaleItemInterface $item

@return float