From a641041c6b1dc926081b252cfd2a56fa6e5a17b7 2014-10-08 18:30:29
From: Jessica B. Hamrick <jhamrick@berkeley.edu>
Date: 2014-10-08 18:30:29
Subject: [PATCH] Only set channels to null when they are fully closed

---

diff --git a/IPython/html/static/services/kernels/js/kernel.js b/IPython/html/static/services/kernels/js/kernel.js
index 76bc9fa..2ae0fcb 100644
--- a/IPython/html/static/services/kernels/js/kernel.js
+++ b/IPython/html/static/services/kernels/js/kernel.js
@@ -355,11 +355,18 @@ define([
      * @method stop_channels
      */
     Kernel.prototype.stop_channels = function () {
+        var that = this;
+        var close = function (c) {
+            return function () {
+                if (that.channels[c].readyState === WebSocket.CLOSED) {
+                    that.channels[c] = null;
+                }
+            };
+        };
         for (var c in this.channels) {
             if ( this.channels[c] !== null ) {
-                this.channels[c].onclose = null;
+                this.channels[c].onclose = close(c);
                 this.channels[c].close();
-                this.channels[c] = null;
             }
         }
     };
@@ -378,6 +385,15 @@ define([
         }
         return true;
     };
+
+    Kernel.prototype.is_fully_disconnected = function () {
+        for (var c in this.channels) {
+            if (this.channels[c] === null) {
+                return true;
+            }
+        }
+        return false;
+    };
     
     // send a message on the Kernel's shell channel
     Kernel.prototype.send_shell_message = function (msg_type, content, callbacks, metadata) {