From 467de651f75f5ea7c5bf649318ebb671a3b1ed1f Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Fri, 19 Jan 2018 13:49:20 -0500
Subject: [PATCH] Guard code from 9b99115b3 needs to be in undo_redo.js too

---
 modules/ui/undo_redo.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/modules/ui/undo_redo.js b/modules/ui/undo_redo.js
index d3f0a3df7..7ec94ae56 100644
--- a/modules/ui/undo_redo.js
+++ b/modules/ui/undo_redo.js
@@ -29,7 +29,8 @@ export function uiUndoRedo(context) {
 
 
     function editable() {
-        return context.editable() && context.mode().id !== 'save';
+        var mode = context.mode();
+        return context.editable() && mode && mode.id !== 'save';
     }