From 6434cc1bdf9900cb3efe7920429a2deffc12e0fb 2014-11-28 10:33:46
From: Matthias Bussonnier <bussonniermatthias@gmail.com>
Date: 2014-11-28 10:33:46
Subject: [PATCH] Merge pull request #7046 from quantopian/fix-history-undo-load

BUG: Prevent users from undoing the initial document load with CTRL-Z.
---

diff --git a/IPython/html/static/edit/js/editor.js b/IPython/html/static/edit/js/editor.js
index 48e2e88..f2db0c8 100644
--- a/IPython/html/static/edit/js/editor.js
+++ b/IPython/html/static/edit/js/editor.js
@@ -35,7 +35,11 @@ function($,
         this.contents.get(this.file_path, {type: 'file', format: 'text'})
             .then(function(model) {
                 cm.setValue(model.content);
-                
+
+                // Setting the file's initial value creates a history entry,
+                // which we don't want.
+                cm.clearHistory();
+
                 // Find and load the highlighting mode
                 var modeinfo = CodeMirror.findModeByMIME(model.mimetype);
                 if (modeinfo) {