From bcd4e5135aa800eb6e8e2bf594c7d9a538f7c7c7 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Fri, 21 Apr 2017 01:29:22 -0400
Subject: [PATCH] Use window.top.location instead of window.location (closes
 #3950)

---
 modules/util/detect.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/modules/util/detect.js b/modules/util/detect.js
index 1a3928c33..c8b24b35f 100644
--- a/modules/util/detect.js
+++ b/modules/util/detect.js
@@ -99,7 +99,14 @@ export function utilDetect(force) {
     }
     setTextDirection(detected.textDirection);
 
-    detected.host = window.location && (window.location.origin + window.location.pathname);
+    // detect host
+    var loc = window.top.location;
+    var origin = loc.origin;
+    if (!origin) {  // for unpatched IE11
+        origin = loc.protocol + '//' + loc.hostname + (loc.port ? ':' + loc.port: '');
+    }
+
+    detected.host = origin + loc.pathname;
 
     detected.filedrop = (window.FileReader && 'ondrop' in window);