make sure unread is > 0 before playing a sound

src/views/tinode-web.jsx

@@ -557,7 +557,8 @@ class TinodeWeb extends React.Component {
       const topic = this.tinode.getTopic(cont.topic);
       const archived = topic && topic.isArchived();
 
-      // New message received
+      // New message received. Maybe the message is from the current user, then unread is 0.
+      if (cont.unread > 0) {
         if (document.hidden) {
           if (this.state.messageSounds && !archived) {
             POP_SOUND.play();
@@ -571,6 +572,7 @@ class TinodeWeb extends React.Component {
           }
           this.resetContactList();
         }
+      }
     } else if (what == 'recv') {
       // Explicitly ignoring "recv" -- it causes no visible updates to contact list.
     } else if (what == 'gone' || what == 'unsub') {

umd/index.dev.js

@@ -4948,6 +4948,7 @@ var TinodeWeb = function (_React$Component) {
         var topic = this.tinode.getTopic(cont.topic);
         var archived = topic && topic.isArchived();
 
+        if (cont.unread > 0) {
           if (document.hidden) {
             if (this.state.messageSounds && !archived) {
               POP_SOUND.play();
@@ -4961,6 +4962,7 @@ var TinodeWeb = function (_React$Component) {
 
             this.resetContactList();
           }
+        }
       } else if (what == 'recv') {} else if (what == 'gone' || what == 'unsub') {
         if (this.state.topicSelected == cont.topic) {
           this.handleTopicSelected(null);