From a9799b70bc1b36dd30c26934ba6b214813999241 Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Sat, 20 Jan 2018 16:37:40 -0500
Subject: [PATCH] code review for aafb85c6c62a: use `contentType`, `instanceof
 document` is unreliable on Firefox

---
 src/js/contentscript.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/js/contentscript.js b/src/js/contentscript.js
index e45ad5a..1ff7d17 100644
--- a/src/js/contentscript.js
+++ b/src/js/contentscript.js
@@ -473,7 +473,7 @@ var collapser = (function() {
     };
 
     var morphNoscript = function(from) {
-        if ( document instanceof XMLDocument ) {
+        if ( /^application\/(?:xhtml\+)?xml/.test(document.contentType) ) {
             var to = document.createElement('span');
             while ( from.firstChild !== null ) {
                 to.appendChild(from.firstChild);