[FIX] mrp_subcontracting: return to subcontract location

Before this commit a returns would select the classic
partner location. However in the case of a subcontractor return
it should be returned to the subcontract location

addons/mrp_subcontracting/tests/test_subcontracting.py

@@ -75,6 +75,14 @@ class TestSubcontractingFlows(TestMrpSubcontractingCommon):
         self.assertEquals(avail_qty_comp2, -1)
         self.assertEquals(avail_qty_finished, 1)
 
+        # Ensure returns to subcontractor location
+        return_form = Form(self.env['stock.return.picking'].with_context(active_id=picking_receipt.id, active_model='stock.picking'))
+        return_wizard = return_form.save()
+        return_picking_id, pick_type_id = return_wizard._create_returns()
+        return_picking = self.env['stock.picking'].browse(return_picking_id)
+        self.assertEqual(len(return_picking), 1)
+        self.assertEqual(return_picking.move_lines.location_dest_id, self.subcontractor_partner1.property_stock_subcontractor)
+
     def test_flow_2(self):
         """ Tick "Resupply Subcontractor on Order" on the components and trigger the creation of
         the subcontracting manufacturing order through a receipt picking. Checks if the resupplying

addons/mrp_subcontracting/wizard/__init__.py

@@ -2,3 +2,4 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 from . import mrp_product_produce
+from . import stock_picking_return

addons/mrp_subcontracting/wizard/stock_picking_return.py

@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo import models
+
+
+class ReturnPicking(models.TransientModel):
+    _inherit = 'stock.return.picking'
+
+    def _prepare_move_default_values(self, return_line, new_picking):
+        vals = super(ReturnPicking, self)._prepare_move_default_values(return_line, new_picking)
+        if return_line.move_id.is_subcontract:
+            vals['location_dest_id'] = self.picking_id.partner_id.property_stock_subcontractor.id
+        return vals