don't preserve fixConsole output in json

IPython/frontend/html/notebook/static/js/codecell.js

@@ -598,7 +598,9 b' var IPython = (function (IPython) {'
             if (last.output_type == 'stream' && json.stream == last.stream){
                 // latest output was in the same stream,
                 // so append directly into its pre tag
-                this.element.find('div.'+subclass).last().find('pre').append(json.text);
+                // escape ANSI & HTML specials:
+                var text = utils.fixConsole(json.text);
+                this.element.find('div.'+subclass).last().find('pre').append(text);
                 return;
             }
         }
@@ -647,6 +649,8 b' var IPython = (function (IPython) {'
 
     CodeCell.prototype.append_text = function (data, element, extra_class) {
         var toinsert = $("<div/>").addClass("box_flex1 output_subarea output_text");
+        // escape ANSI & HTML specials in plaintext:
+        data = utils.fixConsole(data);
         if (extra_class){
             toinsert.addClass(extra_class);
         }

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

@@ -816,7 +816,7 b' var IPython = (function (IPython) {'
         var json = {};
         json.output_type = msg_type;
         if (msg_type === "stream") {
-            json.text = utils.fixConsole(content.data);
+            json.text = content.data;
             json.stream = content.name;
         } else if (msg_type === "display_data") {
             json = this.convert_mime_types(json, content.data);
@@ -826,11 +826,7 b' var IPython = (function (IPython) {'
         } else if (msg_type === "pyerr") {
             json.ename = content.ename;
             json.evalue = content.evalue;
-            var traceback = [];
-            for (var i=0; i<content.traceback.length; i++) {
-                traceback.push(utils.fixConsole(content.traceback[i]));
-            }
-            json.traceback = traceback;
+            json.traceback = content.traceback;
         };
         cell.append_output(json);
         this.dirty = true;
@@ -839,7 +835,7 b' var IPython = (function (IPython) {'
 
     Notebook.prototype.convert_mime_types = function (json, data) {
         if (data['text/plain'] !== undefined) {
-            json.text = utils.fixConsole(data['text/plain']);
+            json.text = data['text/plain'];
         };
         if (data['text/html'] !== undefined) {
             json.html = data['text/html'];