[FIX] purchase_stock: vendor reference

- Create a product A
  MTO, Buy
  Add a supplier S1 and set a specific reference
- Create a product B
  MTO, Buy
  Add a supplier S2 and set a specific reference
- Create a SO with A & B, confirm
- 2 RFQ are created

The first RFQ is created with the correct reference, but not the second
one.

This is because `display_name` depends on context keys: it is computed
once for both products with `partner_id` set as `S1`, while it should be
recomputed for product B with `partner_id` set as `S2`.

In order to avoid this, we use `with_prefetch()` to avoid reusing the
prefetched value.

opw-2176638

closes odoo#44487

Signed-off-by: Nicolas Martinelli (nim) <[email protected]>

addons/purchase_stock/models/stock_rule.py

@@ -221,7 +221,7 @@ def _prepare_purchase_order_line(self, product_id, product_qty, product_uom, com
             price_unit = seller.currency_id._convert(
                 price_unit, po.currency_id, po.company_id, po.date_order or fields.Date.today())
 
-        product_lang = product_id.with_context(
+        product_lang = product_id.with_prefetch().with_context(
             lang=partner.lang,
             partner_id=partner.id,
         )