POS Loyalty Safe Coupon Patch

This custom Odoo module resolves a core Odoo 19 bug in the POS Loyalty module where standard Odoo code makes unsafe direct reads on coupon_id.id of reward lines.

When an order is restored (e.g., during table switching in a restaurant) and references a coupon that is not yet fully loaded in the local client registry, Odoo leaves coupon_id as undefined. Accessing .id on this undefined object crashes the POS UI.

How it works

Without modifying any core Odoo code, this module dynamically patches:

1. PosOrder.getLoyaltyPoints()
2. OrderPaymentValidation.validateOrder()
3. PosStore.postProcessLoyalty()

During their respective execution, it temporarily mocks any missing coupon_id references with { id: 0 }. It also wraps this.data.call during postProcessLoyalty to ensure dummy coupon records with ID 0 are filtered out before being communicated back to the Odoo backend server. After execution, the original undefined state of the coupon is safely restored.

This ensures zero side effects, maximum stability, and clean compatibility with standard/custom addons.