fix(pos): add item in the existing item row when discount is applied

[venkat102]

Issue:
The item is added to the new row when the discount is applied.
ref: 25597

Before:

pos-qty-issue.mp4

After:

pos-qty-fix.mp4

Backport needed for v14 & v15

[ruthra-kumar]

@venkat102
What is the root cause here?

[ruthra-kumar]

Also could you post some replication steps

[venkat102]

@venkat102 What is the root cause here?

When there is a pricing rule to apply the discount on an item with a quantity of more than 3, In POS, the discount is applied when the 3rd is added. But the 4th item was added in a separate row.

This is because the item matches the existing row based on item_code, batch_no, uom, and rate. Since the discount is applied to the existing row, there will be a mismatch in the rate. So, the new item is added in a separate row. Also, the discount is not applied to the new item as the item quantity didn't reach the pricing rule limit.

[venkat102]

Also could you post some replication steps

Steps to replicate:

• create a pricing rule to apply a discount on a item, when the qty reaches a limit (minimum qty of 3)
  

• Open POS Invoice and add the item by clicking the item from the item list (it works fine when the qty is edited manually)

• When it reaches the minimum qty, a discount will be applied and the next item will be added to the new row without a discount