Merge pull request #3741 from minrk/badnbmsg

better message when notebook format is not supported

different messages for bad version and bad JSON.

closes #1592

IPython/html/services/notebooks/filenbmanager.py

@@ -146,8 +146,9 @@ class FileNotebookManager(NotebookManager):
             try:
                 # v1 and v2 and json in the .ipynb files.
                 nb = current.reads(s, u'json')
-            except Exception as e:
-                raise web.HTTPError(500, u'Unreadable JSON notebook: %s' % e)
+            except ValueError as e:
+                msg = u"Unreadable Notebook: %s" % e
+                raise web.HTTPError(400, msg, reason=msg)
         return last_modified, nb
     
     def read_notebook_object(self, notebook_id):

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

@@ -1794,20 +1794,20 @@ var IPython = (function (IPython) {
      * @param {String} errorThrow HTTP error message
      */
     Notebook.prototype.load_notebook_error = function (xhr, textStatus, errorThrow) {
-        if (xhr.status === 500) {
-            var msg = "An error occurred while loading this notebook. Most likely " +
-            "this notebook is in a newer format than is supported by this " +
-            "version of IPython. This version can load notebook formats " +
-            "v"+this.nbformat+" or earlier.";
-            
-            IPython.dialog.modal({
-                title: "Error loading notebook",
-                body : msg,
-                buttons : {
-                    "OK": {}
-                }
-            });
+        if (xhr.status === 400) {
+            var msg = errorThrow;
+        } else if (xhr.status === 500) {
+            var msg = "An unknown error occurred while loading this notebook. " +
+            "This version can load notebook formats " +
+            "v" + this.nbformat + " or earlier.";
         }
+        IPython.dialog.modal({
+            title: "Error loading notebook",
+            body : msg,
+            buttons : {
+                "OK": {}
+            }
+        });
     }
 
     /*********************  checkpoint-related  *********************/