fix(selling): bill re-delivered sales order quantities

erpnext/selling/doctype/sales_order/sales_order.py

@@ -1319,6 +1319,13 @@ def make_delivery_note(source_name, target_doc=None, kwargs=None):
 	return target_doc
 
 
+def get_qty_net_of_returns(so_item) -> float:
+	"""Return the ordered quantity billable after returns and re-deliveries."""
+	qty = flt(so_item.qty)
+
+	return min(qty, max(qty - flt(so_item.returned_qty), flt(so_item.delivered_qty)))
+
+
 @frappe.whitelist()
 def make_sales_invoice(source_name, target_doc=None, ignore_permissions=False, args=None):
 	if args is None:
@@ -1328,10 +1335,40 @@ def make_sales_invoice(source_name, target_doc=None, ignore_permissions=False, a
 
 	# 0 qty is accepted, as the qty is uncertain for some items
 	has_unit_price_items = frappe.db.get_value("Sales Order", source_name, "has_unit_price_items")
+	billed_qty_by_item = None
+	pending_qty_by_item = {}
 
 	def is_unit_price_row(source):
 		return has_unit_price_items and source.qty == 0
 
+	def get_billed_qty_by_item():
+		nonlocal billed_qty_by_item
+
+		if billed_qty_by_item is None:
+			invoice_item = frappe.qb.DocType("Sales Invoice Item")
+			sales_order_item = frappe.qb.DocType("Sales Order Item")
+			rows = (
+				frappe.qb.from_(invoice_item)
+				.inner_join(sales_order_item)
+				.on(invoice_item.so_detail == sales_order_item.name)
+				.select(invoice_item.so_detail, Sum(invoice_item.qty).as_("qty"))
+				.where((invoice_item.docstatus == 1) & (sales_order_item.parent == source_name))
+				.groupby(invoice_item.so_detail)
+			).run(as_dict=True)
+			billed_qty_by_item = {row.so_detail: flt(row.qty) for row in rows}
+
+		return billed_qty_by_item
+
+	def get_pending_qty(source):
+		if source.name not in pending_qty_by_item:
+			billable_qty = get_qty_net_of_returns(source)
+			if source.qty and source.billed_amt:
+				billable_qty -= get_billed_qty_by_item().get(source.name, 0)
+
+			pending_qty_by_item[source.name] = max(flt(billable_qty, source.precision("qty")), 0)
+
+		return pending_qty_by_item[source.name]
+
 	def postprocess(source, target):
 		set_missing_values(source, target)
 		# Get the advance paid Journal Entries in Sales Invoice Advance
@@ -1362,17 +1399,6 @@ def make_sales_invoice(source_name, target_doc=None, ignore_permissions=False, a
 		target.debit_to = get_party_account("Customer", source.customer, source.company)
 
 	def update_item(source, target, source_parent):
-		def get_billed_qty(so_item_name):
-			from frappe.query_builder.functions import Sum
-
-			table = frappe.qb.DocType("Sales Invoice Item")
-			query = (
-				frappe.qb.from_(table)
-				.select(Sum(table.qty).as_("qty"))
-				.where((table.docstatus == 1) & (table.so_detail == so_item_name))
-			)
-			return query.run(pluck="qty")[0] or 0
-
 		if source_parent.has_unit_price_items:
 			# 0 Amount rows (as seen in Unit Price Items) should be mapped as it is
 			pending_amount = flt(source.amount) - flt(source.billed_amt)
@@ -1381,11 +1407,7 @@ def make_sales_invoice(source_name, target_doc=None, ignore_permissions=False, a
 			target.amount = flt(source.amount) - flt(source.billed_amt)
 
 		target.base_amount = target.amount * flt(source_parent.conversion_rate)
-		target.qty = (
+		target.qty = source.qty if is_unit_price_row(source) else get_pending_qty(source)
-			source.qty - get_billed_qty(source.name)
-			if (source.qty and source.billed_amt)
-			else (source.qty if is_unit_price_row(source) else source.qty - source.returned_qty)
-		)
 
 		if source_parent.project:
 			target.cost_center = frappe.db.get_value("Project", source_parent.project, "cost_center")
@@ -1461,13 +1483,17 @@ def make_sales_invoice(source_name, target_doc=None, ignore_permissions=False, a
 					"parent": "sales_order",
 				},
 				"postprocess": update_item,
-				"condition": lambda doc: (
+				"condition": lambda doc: not args.get("skip_item_mapping")
+				and select_item(doc)
+				and (
 					True
 					if is_unit_price_row(doc)
-					else (doc.qty and (doc.base_amount == 0 or abs(doc.billed_amt) < abs(doc.amount)))
+					else (
-				)
+						doc.qty
-				and select_item(doc)
+						and (doc.base_amount == 0 or abs(doc.billed_amt) < abs(doc.amount))
-				and not args.get("skip_item_mapping"),
+						and get_pending_qty(doc) > 0
+					)
+				),
 			},
 			"Sales Taxes and Charges": {
 				"doctype": "Sales Taxes and Charges",