From 546efcc1dbafac20caee6ac11ae55d12311dc9a3 Mon Sep 17 00:00:00 2001
From: Nelson Campos <ncampos@criteriamarathon.com>
Date: Fri, 19 Oct 2018 10:58:47 +0100
Subject: [PATCH] Fix undefined return from getFlip

Navigator setFlip was looking for tiledImage flip state using the getFlip method.
The item this.viewer.world._items[0] can be undefined and trying to use its methods would fail.
---
 src/navigator.js | 2 +-
 src/viewer.js    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/navigator.js b/src/navigator.js
index bb4e08d6..4b2018fb 100644
--- a/src/navigator.js
+++ b/src/navigator.js
@@ -284,7 +284,7 @@ $.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /*
     setFlip: function(state) {
       this.viewport.setFlip(state);
 
-      var flip = ((this.viewport.getFlip() && !this.viewer.world._items[0].getFlip()) || (!this.viewport.getFlip() && this.viewer.world._items[0].getFlip()));
+      var flip = ((this.viewport.getFlip() && this.viewer.world._items[0] && !this.viewer.world._items[0].getFlip()) || (!this.viewport.getFlip() && this.viewer.world._items[0] && this.viewer.world._items[0].getFlip()));
       this.setDisplayTransform(flip ? "scale(-1,1)" : "scale(1,1)");
       return this;
     },
diff --git a/src/viewer.js b/src/viewer.js
index f622829c..ac3701b4 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -3367,7 +3367,7 @@ function updateOnce( viewer ) {
     THIS[ viewer.hash ].animating = animated;
 
     // Update navigator flip transformation
-    if (viewer.navigator && viewer.viewport != "undefined"){
+    if (viewer.navigator && viewer.viewport != undefined){
       viewer.navigator.setFlip(viewer.viewport.getFlip());
     }
     //viewer.profiler.endUpdate();