From 32f62bc565882b989fcef62874c0a90b0241dd1e Mon Sep 17 00:00:00 2001
From: Heinrich Fenkart <hnrch02@gmail.com>
Date: Tue, 16 Dec 2014 06:23:04 +0100
Subject: [PATCH] Modal: Work around IE scrollbars not taking up page width

Fixes #15353.
---
 js/modal.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/js/modal.js b/js/modal.js
index 93891aa4eb..6d68edc1f6 100644
--- a/js/modal.js
+++ b/js/modal.js
@@ -248,7 +248,12 @@
   }
 
   Modal.prototype.checkScrollbar = function () {
-    this.bodyIsOverflowing = document.body.scrollHeight > document.documentElement.clientHeight
+    var fullWindowWidth = window.innerWidth
+    if (!fullWindowWidth) { // workaround for missing window.innerWidth in IE8
+      var documentElementRect = document.documentElement.getBoundingClientRect()
+      fullWindowWidth = documentElementRect.right - Math.abs(documentElementRect.left)
+    }
+    this.bodyIsOverflowing = document.body.clientWidth < fullWindowWidth
     this.scrollbarWidth = this.measureScrollbar()
   }