[FIX] product: fallback onto name for product.partner_ref

Have a product with a partner A as a seller, without any description whatsoever

Do a vendor bill with partner A as the partner.

Add the product onto the lines

Before this commit, the description on the line was "False"

After this commit, we fallback onto the product name if no other reference is set

OPW 1865969
closes #25857

addons/product/models/product.py

@@ -249,7 +249,7 @@ class ProductProduct(models.Model):
     def _compute_partner_ref(self):
         for supplier_info in self.seller_ids:
             if supplier_info.name.id == self._context.get('partner_id'):
-                product_name = supplier_info.product_name or self.default_code
+                product_name = supplier_info.product_name or self.default_code or self.name
                 break
         else:
             product_name = self.name