[FIX] point_of_sale: make card readers work again on payment screen

Swiping a credit card through pos_mercury no longer worked on the
payment screen.

3a74afd21e introduced some special code
in BarcodeEvents for mobile Chrome. This code relies on an invisible
input being filled in by barcode device. On the payment screen the POS
uses a keypress event handler on body to manage input. This handler
preventsDefault which stops the input from being filled in.

It's worth noting that this new approach in
3a74afd21e is not fully equivalent to
the original barcode events handler. Events are not redispatched, so
this effectively disables keyboard input on the payment screen (or
anywhere where it is used).

opw-1888466

closes odoo/odoo#27820

addons/mrp/models/mrp_workorder.py

@@ -317,10 +317,8 @@ class MrpWorkorder(models.Model):
                 if self.product_id.tracking != 'none':
                     qty_to_add = float_round(self.qty_producing * move.unit_factor, precision_rounding=rounding)
                     move._generate_consumed_move_line(qty_to_add, self.final_lot_id)
-                elif len(move._get_move_lines()) < 2:
-                    move.quantity_done += float_round(self.qty_producing * move.unit_factor, precision_rounding=rounding)
                 else:
-                    move._set_quantity_done(move.quantity_done + float_round(self.qty_producing * move.unit_factor, precision_rounding=rounding))
+                    move.quantity_done += float_round(self.qty_producing * move.unit_factor, precision_rounding=rounding)
 
         # Transfer quantities from temporary to final move lots or make them final
         for move_line in self.active_move_line_ids:

addons/point_of_sale/static/src/js/screens.js

@@ -34,6 +34,7 @@ var core = require('web.core');
 var rpc = require('web.rpc');
 var utils = require('web.utils');
 var field_utils = require('web.field_utils');
+var BarcodeEvents = require('barcodes.BarcodeEvents').BarcodeEvents;
 
 var QWeb = core.qweb;
 var _t = core._t;
@@ -1678,6 +1679,13 @@ var PaymentScreenWidget = ScreenWidget.extend({
         // also called explicitly to handle some keydown events that
         // do not generate keypress events.
         this.keyboard_handler = function(event){
+            // On mobile Chrome BarcodeEvents relies on an invisible
+            // input being filled by a barcode device. Let events go
+            // through when this input is focused.
+            if (BarcodeEvents.$barcodeInput && BarcodeEvents.$barcodeInput.is(":focus")) {
+                return;
+            }
+
             var key = '';
 
             if (event.type === "keypress") {