fix(stock): value batched packed-item returns from the original bundle (backport #57327) (#57510)

fix(stock): value batched packed-item returns from the original bundle  (#57327)

* fix(stock): value batched packed-item returns from the original bundle

when a return delivery note or sales invoice bundle is built via the
use_serial_batch_fields / sle-driven path, its voucher_detail_no keeps the
packed item instead of being remapped to the parent dn/si item. the return
valuation lookup then misses and the bundle values at zero, so the sle
stock_value_difference stays wrong even after a repost.

resolve the original dn/si item via the packed item's parent_detail_docname
when the direct lookup fails, so the return values from the original outward
bundle on both submit and repost.

* test(stock): cover batched packed-item return valuation on repost

(cherry picked from commit d37e905322)

Co-authored-by: Sudharsanan Ashok <135326972+Sudharsanan11@users.noreply.github.com>

erpnext/stock/doctype/delivery_note/test_delivery_note.py

@@ -706,6 +706,76 @@ class TestDeliveryNote(FrappeTestCase):
 
 		self.assertEqual(gle_warehouse_amount, 1400)
 
+	def test_return_bundle_voucher_detail_no_as_packed_item(self):
+		"""Return bundle whose voucher_detail_no is the Packed Item (SLE-driven path) must still value on repost."""
+		from erpnext.stock.doctype.delivery_note.delivery_note import make_sales_return
+
+		warehouse = "_Test Warehouse - _TC"
+		packed_item = make_item(
+			properties={
+				"is_stock_item": 1,
+				"has_batch_no": 1,
+				"create_new_batch": 1,
+				"batch_number_series": "BATCH-DN-RET-VDN-.#####",
+			}
+		).name
+		bundle_item = make_item(properties={"is_stock_item": 0, "is_sales_item": 1}).name
+		make_product_bundle(bundle_item, [packed_item], qty=20)
+
+		make_stock_entry(item_code=packed_item, target=warehouse, qty=60, basic_rate=35)
+
+		dn = create_delivery_note(item_code=bundle_item, warehouse=warehouse, qty=3)
+
+		return_dn = make_sales_return(dn.name)
+		return_dn.items[0].qty = -2
+		return_dn.submit()
+		return_dn.reload()
+
+		packed_row = return_dn.packed_items[0]
+		bundle = frappe.get_doc("Serial and Batch Bundle", packed_row.serial_and_batch_bundle)
+
+		# Reproduce the reported state: bundle points at the Packed Item (not the DN Item), valuation at 0.
+		bundle.db_set("voucher_detail_no", packed_row.name)
+		bundle.db_set({"avg_rate": 0, "total_amount": 0})
+		for entry in bundle.entries:
+			entry.db_set({"incoming_rate": 0, "stock_value_difference": 0})
+		packed_row.db_set("incoming_rate", 0)
+		frappe.db.set_value(
+			"Stock Ledger Entry",
+			{
+				"voucher_type": "Delivery Note",
+				"voucher_no": return_dn.name,
+				"item_code": packed_item,
+				"is_cancelled": 0,
+			},
+			{"incoming_rate": 0, "stock_value_difference": 0},
+		)
+
+		frappe.get_doc(
+			doctype="Repost Item Valuation",
+			based_on="Transaction",
+			voucher_type="Delivery Note",
+			voucher_no=return_dn.name,
+			posting_date=return_dn.posting_date,
+			posting_time=return_dn.posting_time,
+		).submit()
+
+		bundle.reload()
+		self.assertEqual(flt(bundle.avg_rate), 35)
+
+		incoming_rate, stock_value_difference = frappe.db.get_value(
+			"Stock Ledger Entry",
+			{
+				"voucher_type": "Delivery Note",
+				"voucher_no": return_dn.name,
+				"item_code": packed_item,
+				"is_cancelled": 0,
+			},
+			["incoming_rate", "stock_value_difference"],
+		)
+		self.assertEqual(flt(incoming_rate), 35)
+		self.assertEqual(flt(stock_value_difference), 1400)
+
 	def test_bin_details_of_packed_item(self):
 		from erpnext.selling.doctype.product_bundle.test_product_bundle import make_product_bundle
 		from erpnext.stock.doctype.item.test_item import make_item

erpnext/stock/doctype/serial_and_batch_bundle/serial_and_batch_bundle.py

@@ -505,6 +505,11 @@ class SerialandBatchBundle(Document):
 			self.child_table, self.voucher_detail_no, field
 		)
 
+		if not return_against_voucher_detail_no and self.voucher_type in ("Delivery Note", "Sales Invoice"):
+			# Bundles built via the use_serial_batch_fields / SLE-driven path keep the Packed Item
+			# as voucher_detail_no (not remapped to the DN/SI Item), so the lookup above misses.
+			return_against_voucher_detail_no = self.get_return_against_packed_item(field)
+
 		filters = [
 			["Serial and Batch Bundle", "voucher_no", "=", return_against],
 			["Serial and Batch Entry", "docstatus", "=", 1],
@@ -548,6 +553,16 @@ class SerialandBatchBundle(Document):
 
 		return valuation_details
 
+	def get_return_against_packed_item(self, field):
+		"""Resolve the original DN/SI Item when a return bundle's voucher_detail_no is the Packed Item."""
+		parent_detail_docname = frappe.db.get_value(
+			"Packed Item", self.voucher_detail_no, "parent_detail_docname"
+		)
+		if not parent_detail_docname:
+			return
+
+		return frappe.db.get_value(self.child_table, parent_detail_docname, field)
+
 	def get_legacy_valuation_rate_for_return_entry(
 		self, return_against, return_against_voucher_detail_no, return_warehouse=None
 	):