make stock qty negative (#13276)

diff --git a/erpnext/controllers/sales_and_purchase_return.py b/erpnext/controllers/sales_and_purchase_return.py
index 4b8bbee..ab189cf 100644
--- a/erpnext/controllers/sales_and_purchase_return.py
+++ b/erpnext/controllers/sales_and_purchase_return.py
@@ -239,6 +239,7 @@
 			target_doc.received_qty = -1* source_doc.received_qty
 			target_doc.rejected_qty = -1* source_doc.rejected_qty
 			target_doc.qty = -1* source_doc.qty
+			target_doc.stock_qty = -1 * source_doc.stock_qty
 			target_doc.purchase_order = source_doc.purchase_order
 			target_doc.purchase_order_item = source_doc.purchase_order_item
 			target_doc.rejected_warehouse = source_doc.rejected_warehouse
@@ -246,6 +247,7 @@
 			target_doc.received_qty = -1* source_doc.received_qty
 			target_doc.rejected_qty = -1* source_doc.rejected_qty
 			target_doc.qty = -1* source_doc.qty
+			target_doc.stock_qty = -1 * source_doc.stock_qty
 			target_doc.purchase_order = source_doc.purchase_order
 			target_doc.purchase_receipt = source_doc.purchase_receipt
 			target_doc.rejected_warehouse = source_doc.rejected_warehouse