[FIX] website_sale_stock: fix warning message if unavailable

Before this commit, the warning to inform the user that a product has
become unavailable was the same, whether the user was on the cart or on
the product page. This commit makes sure that the message is adapted to
the context.

closes odoo/odoo#139332

Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

addons/website_sale_stock/i18n/website_sale_stock.pot

@@ -189,6 +189,13 @@ msgstr ""
 msgid "The following product is now available."
 msgstr ""
 
+#. module: website_sale_stock
+#. odoo-python
+#: code:addons/website_sale_stock/models/sale_order.py:0
+#, python-format
+msgid "The item has not been added to your cart since it is not available."
+msgstr ""
+
 #. module: website_sale_stock
 #. odoo-python
 #: code:addons/website_sale_stock/models/product_product.py:0

addons/website_sale_stock/models/sale_order.py

@@ -41,12 +41,21 @@ class SaleOrder(models.Model):
                         order_line._set_shop_warning_stock(total_cart_qty, available_qty)
                     else:
                         self._set_shop_warning_stock(total_cart_qty, available_qty)
+                    returned_warning = order_line.shop_warning or self.shop_warning
                 else:  # 0 or negative allowed_qty
                     # if existing line: it will be deleted
                     # if no existing line: no line will be created
-                    self.shop_warning = _(
-                        "Some products became unavailable and your cart has been updated. We're sorry for the inconvenience.")
-                return allowed_line_qty, order_line.shop_warning or self.shop_warning
+                    if order_line:
+                        self.shop_warning = _(
+                            "Some products became unavailable and your cart has been updated. We're"
+                            " sorry for the inconvenience."
+                        )
+                        returned_warning = self.shop_warning
+                    else:
+                        returned_warning = _(
+                            "The item has not been added to your cart since it is not available."
+                        )
+                return allowed_line_qty, returned_warning
         return super()._verify_updated_quantity(order_line, product_id, new_qty, **kwargs)
 
     def _get_cart_and_free_qty(self, product, line=None):