From fb9107b3bc2dc6dff6b4fc062f6ea6ee1257685a Mon Sep 17 00:00:00 2001
From: Andrew Patton <andrew@acusti.ca>
Date: Wed, 15 Mar 2017 06:37:17 -0700
Subject: [PATCH] Add guards for Firefox and Safari compatibility

Addresses
https://github.com/facebook/react/pull/7936#issuecomment-270568409 and
https://github.com/summernote/summernote/issues/1057
---
 .../dom/client/ReactInputSelection.js         | 25 +++++++++++--------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/renderers/dom/client/ReactInputSelection.js b/src/renderers/dom/client/ReactInputSelection.js
index 1dd54c0bd6dad..00c88b299ad91 100644
--- a/src/renderers/dom/client/ReactInputSelection.js
+++ b/src/renderers/dom/client/ReactInputSelection.js
@@ -41,22 +41,27 @@ function getElementsWithSelections(acc, win) {
   var doc;
   try {
     doc = win.document;
+    if (!doc) {
+      return acc;
+    }
   } catch (e) {
     return acc;
   }
   var element = null;
   if (win.getSelection) {
     var selection = win.getSelection();
-    var startNode = selection.anchorNode;
-    var endNode = selection.focusNode;
-    var startOffset = selection.anchorOffset;
-    var endOffset = selection.focusOffset;
-    if (startNode && startNode.childNodes.length) {
-      if (startNode.childNodes[startOffset] === endNode.childNodes[endOffset]) {
-        element = startNode.childNodes[startOffset];
-      }
-    } else {
-      element = startNode;
+    if (selection) {
+      var startNode = selection.anchorNode;
+      var endNode = selection.focusNode;
+      var startOffset = selection.anchorOffset;
+      var endOffset = selection.focusOffset;
+      if (startNode && startNode.childNodes.length) {
+          if (startNode.childNodes[startOffset] === endNode.childNodes[endOffset]) {
+              element = startNode.childNodes[startOffset];
+          }
+      } else {
+          element = startNode;
+      }    
     }
   } else if (doc.selection) {
     var range = doc.selection.createRange();