From 4e249666f1a5d71f908a81ab26650e85c3a42f01 Mon Sep 17 00:00:00 2001
From: Alexander Grimalovsky <alexander.grimalovsky@gmail.com>
Date: Thu, 8 Dec 2016 16:08:07 +0700
Subject: [PATCH]  - Updated global object choosing to avoid passing freezed
 objects into script  - Updated postMessage test to avoid false positive
 inside Firefox Add-on SDK based extensions Should fix #58

---
 setImmediate.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/setImmediate.js b/setImmediate.js
index 3c1b06e..db4eb1f 100644
--- a/setImmediate.js
+++ b/setImmediate.js
@@ -84,7 +84,7 @@
     function canUsePostMessage() {
         // The test against `importScripts` prevents this implementation from being installed inside a web worker,
         // where `global.postMessage` means something completely different and can't be used for this purpose.
-        if (global.postMessage && !global.importScripts) {
+        if (global.postMessage && !global.importScripts && !(global.port && global.port.emit)) {
             var postMessageIsAsynchronous = true;
             var oldOnMessage = global.onmessage;
             global.onmessage = function() {
@@ -183,4 +183,4 @@
 
     attachTo.setImmediate = setImmediate;
     attachTo.clearImmediate = clearImmediate;
-}(typeof self === "undefined" ? typeof global === "undefined" ? this : global : self));
+}(typeof self === "undefined" || !Object.isExtensible(self) ? typeof global === "undefined" || !Object.isExtensible(global) ? this : global : self));