From a76ac95f7cd49772114e76bd3643a59e11d684c2 Mon Sep 17 00:00:00 2001
From: 6ea86b96 <6ea86b96@gmail.com>
Date: Sun, 25 Jun 2017 14:08:29 +0700
Subject: [PATCH] Don't call history.back when there is no previous history

---
 ui/js/actions/app.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ui/js/actions/app.js b/ui/js/actions/app.js
index 669ce0010..35049d435 100644
--- a/ui/js/actions/app.js
+++ b/ui/js/actions/app.js
@@ -61,6 +61,8 @@ export function doChangePath(path) {
 
 export function doHistoryBack() {
   return function(dispatch, getState) {
+    if (!history.state) return;
+
     history.back();
   };
 }