[FIX] stock: recompute on picking assign

- Create a kit (phantom BOM), composed of 2 different products A and B
- Create a SO, sell a random stockable product, confirm and validate the
  picking.
- Edit the SO, add the kit and save.

Two pickings are created, one for product A and one for product B.

Commit 8fe8ca9948 forces the recomputation of the stock moves, in order
to be able to find a newly created picking. This should actually be done
after each picking creation.

opw-725929

addons/stock/models/stock_move.py

@@ -412,15 +412,8 @@ class StockMove(models.Model):
         type (moves should already have them identical). Otherwise, create a new
         picking to assign them to. """
         Picking = self.env['stock.picking']
-
-        # If this method is called in batch by a write on a one2many and
-        # at some point had to create a picking, some next iterations could
-        # try to find back the created picking. As we look for it by searching
-        # on some computed fields, we have to force a recompute, else the
-        # record won't be found.
-        self.recompute()
-
         for move in self:
+            recompute = False
             picking = Picking.search([
                 ('group_id', '=', move.group_id.id),
                 ('location_id', '=', move.location_id.id),
@@ -429,8 +422,17 @@ class StockMove(models.Model):
                 ('printed', '=', False),
                 ('state', 'in', ['draft', 'confirmed', 'waiting', 'partially_available', 'assigned'])], limit=1)
             if not picking:
+                recompute = True
                 picking = Picking.create(move._get_new_picking_values())
             move.write({'picking_id': picking.id})
+
+            # If this method is called in batch by a write on a one2many and
+            # at some point had to create a picking, some next iterations could
+            # try to find back the created picking. As we look for it by searching
+            # on some computed fields, we have to force a recompute, else the
+            # record won't be found.
+            if recompute:
+                move.recompute()
         return True
     _picking_assign = assign_picking