From df418c6a62859db70d56a2e58d77cb721d4c8a2d Mon Sep 17 00:00:00 2001
From: Bussonnier Matthias <bussonniermatthias@gmail.com>
Date: Tue, 16 Dec 2014 14:04:20 +0100
Subject: [PATCH 1/2] fix restore checkpoint add an empty cell

---
 IPython/html/static/notebook/js/notebook.js | 23 ++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/IPython/html/static/notebook/js/notebook.js b/IPython/html/static/notebook/js/notebook.js
index 0d9e6f15d..ab41fdebb 100644
--- a/IPython/html/static/notebook/js/notebook.js
+++ b/IPython/html/static/notebook/js/notebook.js
@@ -766,6 +766,27 @@ define([
 
     // Insertion, deletion.
 
+    /**
+     * Delete a cell from the notebook without any precautions
+     * Needed to reload checkpoints and other things like that.
+     * 
+     * @param {integer} [index] - cell's numeric index
+     * @return {Notebook} This notebook
+     */
+    Notebook.prototype.unsafe_delete_cell = function (index) {
+        var i = this.index_or_selected(index);
+        var cell = this.get_cell(i);
+
+        $('#undelete_cell').addClass('disabled');
+        if (this.is_valid_cell_index(i)) {
+            var old_ncells = this.ncells();
+            var ce = this.get_cell_element(i);
+            ce.remove();
+            this.set_dirty(true);
+        }
+        return this;
+    };
+
     /**
      * Delete a cell from the notebook.
      * 
@@ -1734,7 +1755,7 @@ define([
         var i;
         for (i=0; i<ncells; i++) {
             // Always delete cell 0 as they get renumbered as they are deleted.
-            this.delete_cell(0);
+            this.unsafe_delete_cell(0);
         }
         // Save the metadata and name.
         this.metadata = content.metadata;

From f0c5de7c7e23a55c4595706fee08d45e67bb86c5 Mon Sep 17 00:00:00 2001
From: Bussonnier Matthias <bussonniermatthias@gmail.com>
Date: Tue, 16 Dec 2014 18:13:14 +0100
Subject: [PATCH 2/2] make method private

---
 IPython/html/static/notebook/js/notebook.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/IPython/html/static/notebook/js/notebook.js b/IPython/html/static/notebook/js/notebook.js
index ab41fdebb..94be416de 100644
--- a/IPython/html/static/notebook/js/notebook.js
+++ b/IPython/html/static/notebook/js/notebook.js
@@ -773,7 +773,7 @@ define([
      * @param {integer} [index] - cell's numeric index
      * @return {Notebook} This notebook
      */
-    Notebook.prototype.unsafe_delete_cell = function (index) {
+    Notebook.prototype._unsafe_delete_cell = function (index) {
         var i = this.index_or_selected(index);
         var cell = this.get_cell(i);
 
@@ -1755,7 +1755,7 @@ define([
         var i;
         for (i=0; i<ncells; i++) {
             // Always delete cell 0 as they get renumbered as they are deleted.
-            this.unsafe_delete_cell(0);
+            this._unsafe_delete_cell(0);
         }
         // Save the metadata and name.
         this.metadata = content.metadata;