Merge pull request #6766 from takluyver/i6764

Open ipynb download in a new window instead of changing the URL

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

@@ -112,7 +112,7 define([
                 notebook_path,
                 notebook_name
             );
-            window.location.assign(url);
+            window.open(url);
         });
         
         this.element.find('#print_preview').click(function () {