[IMP] bus: allow bus to restart polling on demand

The problem was that the bus didn't listen to new channels when they were
registered until the end of the current longpoll. This allows mail to manually
restart the polling.

addons/bus/static/src/js/bus.js

@@ -1,4 +1,5 @@
 odoo.define('bus.bus', function (require) {
+"use strict";
 
 var session = require('web.session');
 var Widget = require('web.Widget');
@@ -40,11 +41,15 @@ bus.Bus = Widget.extend({
         var self = this;
         self.activated = true;
         var data = {'channels': self.channels, 'last': self.last, 'options' : self.options};
-        session.rpc('/longpolling/poll', data, {shadow : true}).then(function(result) {
+        this.current_poll = $.Deferred();
+        this.current_poll.then(function (result) {
             _.each(result, _.bind(self.on_notification, self));
             if(!self.stop){
                 self.poll();
             }
+        });
+        session.rpc('/longpolling/poll', data, {shadow : true}).then(function(result) {
+            self.current_poll.resolve(result);
         }, function(unused, e) {
             // no error popup if request is interrupted or fails for any reason
             e.preventDefault();
@@ -58,6 +63,12 @@ bus.Bus = Widget.extend({
         }
         this.trigger("notification", [notification.channel, notification.message]);
     },
+    restart_poll: function () {
+        if (this.current_poll) {
+            this.current_poll.fail();
+        }
+        this.poll();
+    },
     add_channel: function(channel){
         if(!_.contains(this.channels, channel)){
             this.channels.push(channel);