Added sales as origin for ShipmentOutReturn

__init__.py

@@ -8,4 +8,5 @@ from .shipment import *
 def register():
     Pool.register(
         ShipmentOut,
+        ShipmentOutReturn,
         module='stock_origin_sale', type_='model')

shipment.py

@@ -4,7 +4,7 @@
 from trytond.model import fields
 from trytond.pool import Pool, PoolMeta
 
-__all__ = ['ShipmentOut']
+__all__ = ['ShipmentOut', 'ShipmentOutReturn']
 __metaclass__ = PoolMeta
 
 
@@ -25,3 +25,22 @@ class ShipmentOut:
     @classmethod
     def _get_origin(cls):
         return super(ShipmentOut, cls)._get_origin() + ['sale.sale']
+
+
+class ShipmentOutReturn:
+    __name__ = 'stock.shipment.out.return'
+
+    @classmethod
+    def get_origin_value(cls, shipments, name):
+        SaleLine = Pool().get('sale.line')
+        origin = super(ShipmentOutReturn, cls).get_origin_value(shipments, name)
+        for shipment in shipments:
+            for m in shipment.incoming_moves:
+                if m.origin and isinstance(m.origin, SaleLine):
+                    origin[shipment.id] = 'sale.sale,%s' % (m.origin.sale.id)
+                    break
+        return origin
+
+    @classmethod
+    def _get_origin(cls):
+        return super(ShipmentOutReturn, cls)._get_origin() + ['sale.sale']