itemNum 保存的数值计算的bug修复

biz-hd/purchase/classes/PurchaseClass.php

@@ -330,7 +330,7 @@ class PurchaseClass extends BaseClass
             $addNum = $arr['addNum']; //新增的数值
             $product = $arr['product'];
             $ratio = $product->ratio;
-            $newStock = bcadd($product->stock, $addNum);
+            $newStock = bcadd($product->stock, $addNum, 2);
             $formNum = ProductClass::formatStock($newStock, $ratio); //花材的库存转换
             $itemInfo[] = [
                 'productId' => $productId,