[MERGE] Fix ported from 6.0.0: Can't set a default origin for stock p…

…ickings at duplication time

https://launchpad.net/bugs/1098557

addons/stock/stock.py

@@ -721,8 +721,9 @@ def copy(self, cr, uid, id, default=None, context=None):
         if ('name' not in default) or (picking_obj.name == '/'):
             seq_obj_name = 'stock.picking.' + picking_obj.type
             default['name'] = self.pool.get('ir.sequence').get(cr, uid, seq_obj_name)
-            default['origin'] = ''
             default['backorder_id'] = False
+        if 'origin' not in default:
+            default['origin'] = ''
         if 'invoice_state' not in default and picking_obj.invoice_state == 'invoiced':
             default['invoice_state'] = '2binvoiced'
         res = super(stock_picking, self).copy(cr, uid, id, default, context)