feat: restrict split or transfer of discount and manual adjustment lines in POS split bill screen

README.md

@@ -5,6 +5,7 @@ This Odoo 19 module enhances the security and auditability of the Point of Sale
 ## Features
 
 - **Mandatory PIN on Table Selection**: Prevents unauthorized access to tables. Every table selection triggers a PIN prompt to identify the employee taking the order.
+- **Block Discount Split/Transfer**: Prevents discount lines (including reward lines, global discounts, and negative price/manual adjustment lines) from being manually split or transferred on the POS split bill screen.
 - **Mandatory PIN on Load Order**: Enforces PIN entry when a draft order is loaded/resumed from the Orders tab (`TicketScreen`).
 - **Mandatory PIN on Payment**: Requires PIN authentication before processing payments to ensure the transaction is handled by an authorized employee.
 - **Role-Based Payment Gating**: Cross-checks employee roles (using `pos_employee_role`) to prevent roles like 'waiter' from processing payments.

static/src/app/models/pos_order_line.js

@@ -0,0 +1,20 @@
+import { PosOrderline } from "@point_of_sale/app/models/pos_order_line";
+import { patch } from "@web/core/utils/patch";
+
+patch(PosOrderline.prototype, {
+    get isDiscountLine() {
+        return (
+            this.is_reward_line ||
+            (this.config.discount_product_id && this.product_id.id === this.config.discount_product_id.id) ||
+            this.price_unit < 0 ||
+            this.prices?.total_included < 0
+        );
+    },
+
+    isGlobalDiscountApplicable() {
+        if (this.isDiscountLine) {
+            return false;
+        }
+        return super.isGlobalDiscountApplicable();
+    },
+});

static/src/app/screens/split_bill_screen/split_bill_screen.js

@@ -0,0 +1,13 @@
+/** @odoo-module */
+
+import { patch } from "@web/core/utils/patch";
+import { SplitBillScreen } from "@pos_restaurant/app/screens/split_bill_screen/split_bill_screen";
+
+patch(SplitBillScreen.prototype, {
+    onClickLine(line) {
+        if (line.isDiscountLine) {
+            return;
+        }
+        super.onClickLine(...arguments);
+    }
+});

static/src/app/screens/split_bill_screen/split_bill_screen.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<templates id="template" xml:space="preserve">
+    <t t-name="pos_custom_access.SplitBillScreen" t-inherit="pos_restaurant.SplitBillScreen" t-inherit-mode="extension">
+        <xpath expr="//Orderline" position="attributes">
+            <attribute name="t-if">!line.isDiscountLine</attribute>
+        </xpath>
+    </t>
+</templates>