fix: reposting not fixing valuation rate for sales return using movin… (backport #38895) (#38897)

* fix: reposting not fixing valuation rate for sales return using movin… (#38895)

fix: reposting not fixing valuation rate for sales return using moving average method
(cherry picked from commit 3a668bbe9694fdd6e8265869c6943e42f889ac41)

# Conflicts:
#	erpnext/stock/stock_ledger.py

* chore: fix conflicts

---------

Co-authored-by: rohitwaghchaure <rohitw1991@gmail.com>

erpnext/controllers/selling_controller.py

@@ -438,7 +438,9 @@ class SellingController(StockController):
 				# Get incoming rate based on original item cost based on valuation method
 				qty = flt(d.get("stock_qty") or d.get("actual_qty"))
 
-				if not d.incoming_rate:
+				if not d.incoming_rate or (
+					get_valuation_method(d.item_code) == "Moving Average" and self.get("is_return")
+				):
 					d.incoming_rate = get_incoming_rate(
 						{
 							"item_code": d.item_code,

erpnext/stock/doctype/delivery_note/test_delivery_note.py

@@ -1425,6 +1425,59 @@ class TestDeliveryNote(FrappeTestCase):
 
 		self.assertAlmostEqual(dn1.items[0].incoming_rate, 250.0)
 
+	def test_sales_return_valuation_for_moving_average_case2(self):
+		# Make DN return
+		# Make Bakcdated Purchase Receipt and check DN return valuation rate
+		# The rate should be recalculate based on the backdated purchase receipt
+		frappe.flags.print_debug_messages = False
+		item_code = make_item(
+			"_Test Item Sales Return with MA Case2",
+			{"is_stock_item": 1, "valuation_method": "Moving Average", "stock_uom": "Nos"},
+		).name
+
+		make_stock_entry(
+			item_code=item_code,
+			target="_Test Warehouse - _TC",
+			qty=5,
+			basic_rate=100.0,
+			posting_date=add_days(nowdate(), -5),
+		)
+
+		dn = create_delivery_note(
+			item_code=item_code,
+			warehouse="_Test Warehouse - _TC",
+			qty=5,
+			rate=500,
+			posting_date=add_days(nowdate(), -4),
+		)
+
+		returned_dn = create_delivery_note(
+			is_return=1,
+			item_code=item_code,
+			return_against=dn.name,
+			qty=-5,
+			rate=500,
+			company=dn.company,
+			warehouse="_Test Warehouse - _TC",
+			expense_account="Cost of Goods Sold - _TC",
+			cost_center="Main - _TC",
+			posting_date=add_days(nowdate(), -1),
+		)
+
+		self.assertAlmostEqual(returned_dn.items[0].incoming_rate, 100.0)
+
+		# Make backdated purchase receipt
+		make_stock_entry(
+			item_code=item_code,
+			target="_Test Warehouse - _TC",
+			qty=5,
+			basic_rate=200.0,
+			posting_date=add_days(nowdate(), -3),
+		)
+
+		returned_dn.reload()
+		self.assertAlmostEqual(returned_dn.items[0].incoming_rate, 200.0)
+
 
 def create_delivery_note(**args):
 	dn = frappe.new_doc("Delivery Note")

erpnext/stock/stock_ledger.py

@@ -25,6 +25,7 @@ from erpnext.stock.doctype.stock_reservation_entry.stock_reservation_entry impor
 )
 from erpnext.stock.utils import (
 	get_incoming_outgoing_rate_for_cancel,
+	get_incoming_rate,
 	get_or_make_bin,
 	get_stock_balance,
 	get_valuation_method,
@@ -841,6 +842,26 @@ class update_entries_after(object):
 					get_rate_for_return,  # don't move this import to top
 				)
 
+				if self.valuation_method == "Moving Average":
+					rate = get_incoming_rate(
+						{
+							"item_code": sle.item_code,
+							"warehouse": sle.warehouse,
+							"posting_date": sle.posting_date,
+							"posting_time": sle.posting_time,
+							"qty": sle.actual_qty,
+							"serial_no": sle.get("serial_no"),
+							"batch_no": sle.get("batch_no"),
+							"serial_and_batch_bundle": sle.get("serial_and_batch_bundle"),
+							"company": sle.company,
+							"voucher_type": sle.voucher_type,
+							"voucher_no": sle.voucher_no,
+							"allow_zero_valuation": self.allow_zero_rate,
+							"sle": sle.name,
+						}
+					)
+
+				else:
 					rate = get_rate_for_return(
 						sle.voucher_type,
 						sle.voucher_no,
@@ -848,7 +869,6 @@ class update_entries_after(object):
 						voucher_detail_no=sle.voucher_detail_no,
 						sle=sle,
 					)
-
 			elif (
 				sle.voucher_type in ["Purchase Receipt", "Purchase Invoice"]
 				and sle.voucher_detail_no