fix(JitsiConference.leave): Promise and logic

JitsiConference.js

     return this.room && this.room.joined;
 };
 
-/**
- * Leaves the conference and calls onMemberLeft for every participant.
- */
-JitsiConference.prototype._leaveRoomAndRemoveParticipants = function () {
-    // remove all participants
-    this.getParticipants().forEach(function (participant) {
-        this.onMemberLeft(participant.getJid());
-    }.bind(this));
-
-    // leave the conference
-    if (this.room) {
-        this.room.leave();
-    }
-
-    this.room = null;
-};
-
 /**
  * Leaves the conference.
  * @returns {Promise}
  */
 JitsiConference.prototype.leave = function () {
-    var conference = this;
-
     if (this.participantConnectionStatus) {
         this.participantConnectionStatus.dispose();
         this.participantConnectionStatus = null;
     }
 
-    this.statistics.stopCallStats();
+    this.getLocalTracks().forEach(track => this.onTrackRemoved(track));
+
     this.rtc.closeAllDataChannels();
+    if(this.statistics)
+        this.statistics.dispose();
 
-    return Promise.all(
-        conference.getLocalTracks().map(function (track) {
-            return conference.removeTrack(track);
-        })
-    ).then(this._leaveRoomAndRemoveParticipants.bind(this))
-    .catch(function (error) {
-        logger.error(error);
-        GlobalOnErrorHandler.callUnhandledRejectionHandler(
-            {promise: this, reason: error});
-        // We are proceeding with leaving the conference because room.leave may
-        // succeed.
-        this._leaveRoomAndRemoveParticipants();
-        return Promise.resolve();
-    }.bind(this));
+    // leave the conference
+    if (this.room) {
+        let room = this.room;
+        this.room = null;
+        return room.leave().catch(() => {
+            // remove all participants because currently the conference won't
+            // be usable anyway. This is done on success automatically by the
+            // ChatRoom instance.
+            this.getParticipants().forEach(
+                participant => this.onMemberLeft(participant.getJid()));
+        });
+    }
+
+    // If this.room == null we are calling second time leave().
+    return Promise.reject(
+        new Error("The conference is has been already left"));
 };
 
 /**

JitsiConferenceEventManager.js

     });
 
     if(conference.statistics) {
-        chatRoom.addListener(XMPPEvents.DISPOSE_CONFERENCE,
-            function () {
-                conference.statistics.dispose();
-            });
-
         chatRoom.addListener(XMPPEvents.CONNECTION_ICE_FAILED,
             function (pc) {
                 conference.statistics.sendIceConnectionFailedEvent(pc);

modules/statistics/statistics.js

 };
 
 Statistics.prototype.dispose = function () {
+    this.stopCallStats();
     this.stopRemoteStats();
     if(this.eventEmitter)
         this.eventEmitter.removeAllListeners();

modules/xmpp/ChatRoom.js

 
 /**
  * Leaves the room. Closes the jingle session.
+ * @returns {Promise} which is resolved if XMPPEvents.MUC_LEFT is received less
+ * than 5s after sending presence unavailable. Otherwise the promise is
+ * rejected.
  */
 ChatRoom.prototype.leave = function () {
     this._dispose();
-    this.doLeave();
+    return new Promise((resolve, reject) => {
+        let timeout = setTimeout(() => onMucLeft(true), 5000);
+        let eventEmitter = this.eventEmitter;
+        function onMucLeft(doReject = false) {
+            eventEmitter.removeListener(XMPPEvents.MUC_LEFT, onMucLeft);
+            clearTimeout(timeout);
+            if(doReject) {
+                // the timeout expired
+                reject(new Error("The timeout for the confirmation about " +
+                    "leaving the room expired."));
+            } else {
+                resolve();
+            }
+        }
+        eventEmitter.on(XMPPEvents.MUC_LEFT, onMucLeft);
+        this.doLeave();
+    });
 };
 
 /**
     if (this.session) {
         this.session.close();
     }
-    this.eventEmitter.emit(XMPPEvents.DISPOSE_CONFERENCE);
 };
 
 module.exports = ChatRoom;

service/xmpp/XMPPEvents.js

     // Designates an event indicating that the display name of a participant
     // has changed.
     DISPLAY_NAME_CHANGED: "xmpp.display_name_changed",
-    DISPOSE_CONFERENCE: "xmpp.dispose_conference",
     ETHERPAD: "xmpp.etherpad",
     FOCUS_DISCONNECTED: 'xmpp.focus_disconnected',
     FOCUS_LEFT: "xmpp.focus_left",