fix: incoming rate for the stand-alone credit note

(cherry picked from commit b06eca8dcb)

# Conflicts:
#	erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py

erpnext/controllers/sales_and_purchase_return.py

@@ -680,6 +680,14 @@ def get_rate_for_return(
 				raise_error_if_no_rate=False,
 			)
 
+	if not rate and voucher_type in ["Sales Invoice", "Delivery Note"]:
+		details = frappe.db.get_value(
+			voucher_type + " Item", voucher_detail_no, ["rate", "allow_zero_valuation_rate"], as_dict=1
+		)
+
+		if details and not details.allow_zero_valuation_rate:
+			rate = flt(details.rate)
+
 	return rate
 
 

erpnext/controllers/selling_controller.py

@@ -525,6 +525,15 @@ class SellingController(StockController):
 						self.doctype, self.name, d.item_code, self.return_against, item_row=d
 					)
 
+				if (
+					self.get("is_return")
+					and not d.incoming_rate
+					and not self.get("return_against")
+					and not self.is_internal_transfer()
+					and not d.get("allow_zero_valuation_rate")
+				):
+					d.incoming_rate = d.rate
+
 				# For internal transfers use incoming rate as the valuation rate
 				if self.is_internal_transfer():
 					if self.doctype == "Delivery Note" or self.get("update_stock"):