[IMP] stock,mrp: origin of scrap move

If the user has not filled in the origin in the scrap object,
we set it to be its associated picking or production order if any.

addons/mrp/models/stock_scrap.py

@@ -41,6 +41,7 @@ class StockScrap(models.Model):
     def _prepare_move_values(self):
         vals = super(StockScrap, self)._prepare_move_values()
         if self.production_id:
+            vals['origin'] = vals['origin'] or self.production_id.name
             if self.product_id in self.production_id.move_finished_ids.mapped('product_id'):
                 vals.update({'production_id': self.production_id.id})
             else:

addons/stock/models/stock_scrap.py

@@ -93,7 +93,7 @@ class StockScrap(models.Model):
         self.ensure_one()
         return {
             'name': self.name,
-            'origin': self.origin,
+            'origin': self.origin or self.picking_id.name,
             'product_id': self.product_id.id,
             'product_uom': self.product_uom_id.id,
             'product_uom_qty': self.scrap_qty,