Minor fixes in sales return
diff --git a/erpnext/stock/doctype/stock_entry/stock_entry.py b/erpnext/stock/doctype/stock_entry/stock_entry.py
index cbe8c29..ac81f88 100644
--- a/erpnext/stock/doctype/stock_entry/stock_entry.py
+++ b/erpnext/stock/doctype/stock_entry/stock_entry.py
@@ -297,8 +297,8 @@
 						frappe.DoesNotExistError)
 
 				# validate quantity <= ref item's qty - qty already returned
-				ref_item = ref.doc.getone({"item_code": item.item_code})
-				returnable_qty = ref_item.qty - flt(already_returned_item_qty.get(item.item_code))
+				ref_item_qty = sum([flt(d.qty) for d in ref.doc.get({"item_code": item.item_code})])
+				returnable_qty = ref_item_qty - flt(already_returned_item_qty.get(item.item_code))
 				if not returnable_qty:
 					frappe.throw(_("Item {0} has already been returned").format(item.item_code), StockOverReturnError)
 				elif item.transfer_qty > returnable_qty: