save packing list after cleanup
diff --git a/erpnext/selling/doctype/sales_common/sales_common.py b/erpnext/selling/doctype/sales_common/sales_common.py
index 66d786e..6e46b9a 100644
--- a/erpnext/selling/doctype/sales_common/sales_common.py
+++ b/erpnext/selling/doctype/sales_common/sales_common.py
@@ -517,6 +517,7 @@
 		for d in getlist(obj.doclist, 'packing_details'):
 			if [d.parent_item, d.parent_detail_docname] not in parent_items:
 				d.parent = ''
+				d.save()
 
 
 	# Get total in words