[FIX] pos_product_multi_barcode: incoherent data

If a `barcode` is already in `product_by_barcode`, do not override
it, as Odoo does with `product_by_id`. This can lead to incoherent
data if something changes after product is first loaded and then
reloads (if limited loading is enabled), or it is modified in
`product_by_id` and not in `product_by_barcode`.

pos_product_multi_barcode/static/src/js/db.js

@@ -20,6 +20,9 @@ odoo.define("pos_product_multi_barcode.db", function (require) {
                 var barcodes = JSON.parse(product.barcodes_json);
 
                 barcodes.forEach(function (barcode) {
+                    if (barcode in self.product_by_barcode) {
+                        return;
+                    }
                     self.product_by_barcode[barcode] = product;
                 });
             });