Use Session.restart in Notebook.start_session

IPython/html/static/notebook/js/notebook.js

@@ -1558,45 +1558,25 b' define(['
             throw new session.SessionAlreadyStarting();
         }
         this._session_starting = true;
-        
-        if (this.session !== null) {
-            var s = this.session;
-            this.session = null;
-            // need to start the new session in a callback after delete,
-            // because javascript does not guarantee the ordering of AJAX requests (?!)
-            s.delete(function () {
-                    // on successful delete, start new session
-                    that._session_starting = false;
-                    that.start_session(kernel_name);
-                }, function (jqXHR, status, error) {
-                    // log the failed delete, but still create a new session
-                    // 404 just means it was already deleted by someone else,
-                    // but other errors are possible.
-                    utils.log_ajax_error(jqXHR, status, error);
-                    that._session_starting = false;
-                    that.start_session(kernel_name);
-                }
-            );
-            return;
-        }
-        
-        
-    
-        this.session = new session.Session({
+
+        var options = {
             base_url: this.base_url,
             ws_url: this.ws_url,
             notebook_path: this.notebook_path,
             notebook_name: this.notebook_name,
-            // For now, create all sessions with the 'python' kernel, which is the
-            // default. Later, the user will be able to select kernels. This is
-            // overridden if KernelManager.kernel_cmd is specified for the server.
             kernel_name: kernel_name,
-            notebook: this});
+            notebook: this
+        };
 
-        this.session.start(
-            $.proxy(this._session_started, this),
-            $.proxy(this._session_start_failed, this)
-        );
+        var success = $.proxy(this._session_started, this);
+        var failure = $.proxy(this._session_start_failed, this);
+
+        if (this.session !== null) {
+            this.session.restart(options, success, failure);
+        } else {
+            this.session = new session.Session(options);
+            this.session.start(success, failure);
+        }
     };