[FIX] barcodes: don't redraw form twice

When scanning a command barcode, the view shouldn't be redrawn
after the operation corresponding to the command is executed,
for two reasons: first, it is useless as the view has already
been reloaded, and second, it may cause issues if it has been
destroyed meanwhile.

For example, when scanning barcode O-CMD.MAIN-MENU from a
picking form view: a do_action is performed to go back to the
main barcode client action (so the current form view is destroyed),
but an handler tried to redrawn the destroyed form view, which
produced a crash because the session was required by Date fields,
and it couldn't be provided (there were no more parent listening
to provide it).

addons/barcodes/static/src/js/barcode_form_view.js

@@ -240,8 +240,13 @@ FormController.include({
             if (prefixed && !hasCommand) {
                 self.do_warn(_t('Error : Barcode command is undefined'), barcode);
             }
-            return $.when.apply($, defs).then(function () {
-                self.update({}, {reload: false});
+            return self.alive($.when.apply($, defs)).then(function () {
+                if (!prefixed) {
+                    // redraw the view if we scanned a real barcode (required if
+                    // we manually apply the change in JS, e.g. incrementing the
+                    // quantity)
+                    self.update({}, {reload: false});
+                }
             });
         });
     },