From df00507fb37bc04b165d7795620d0af6dde8b298 Mon Sep 17 00:00:00 2001
From: Anthony Van de Gejuchte <anthonyvdgent@gmail.com>
Date: Sun, 22 May 2016 21:49:12 +0200
Subject: [PATCH 1/2] Add Symbol to builtins

---
 lib/propmangle.js      |  2 +-
 test/mocha/builtins.js | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 test/mocha/builtins.js

diff --git a/lib/propmangle.js b/lib/propmangle.js
index 050f07d7..ae2a3f44 100644
--- a/lib/propmangle.js
+++ b/lib/propmangle.js
@@ -47,7 +47,7 @@ function find_builtins() {
     var a = [];
     [ Object, Array, Function, Number,
       String, Boolean, Error, Math,
-      Date, RegExp
+      Date, RegExp, Symbol
     ].forEach(function(ctor){
         Object.getOwnPropertyNames(ctor).map(add);
         if (ctor.prototype) {
diff --git a/test/mocha/builtins.js b/test/mocha/builtins.js
new file mode 100644
index 00000000..2782830a
--- /dev/null
+++ b/test/mocha/builtins.js
@@ -0,0 +1,26 @@
+var UglifyJS = require("../../");
+var assert = require("assert");
+
+describe("builtins", function() {
+    it ("Should not mangle builtins", function() {
+        var test = "function foo(something){\n" +
+            "    return [Object,Array,Function,Number,String,Boolean,Error,Math,Date,RegExp,Symbol,something];\n" +
+            "};";
+
+        var result = UglifyJS.minify(test, {fromString: true, parse: {bare_returns: true}}).code;
+
+        assert.strictEqual(result.indexOf("something"), -1);
+
+        assert.notEqual(result.indexOf("Object"), -1);
+        assert.notEqual(result.indexOf("Array"), -1);
+        assert.notEqual(result.indexOf("Function"), -1);
+        assert.notEqual(result.indexOf("Number"), -1);
+        assert.notEqual(result.indexOf("String"), -1);
+        assert.notEqual(result.indexOf("Boolean"), -1);
+        assert.notEqual(result.indexOf("Error"), -1);
+        assert.notEqual(result.indexOf("Math"), -1);
+        assert.notEqual(result.indexOf("Date"), -1);
+        assert.notEqual(result.indexOf("RegExp"), -1);
+        assert.notEqual(result.indexOf("Symbol"), -1);
+    });
+});

From 5cfefd0c41ffba3df0a29d0913b7c6abf3b110ac Mon Sep 17 00:00:00 2001
From: Anthony Van de Gejuchte <anthonyvdgent@gmail.com>
Date: Sun, 22 May 2016 22:08:18 +0200
Subject: [PATCH 2/2] Make sure Symbol is defined on older js engines

---
 lib/propmangle.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/propmangle.js b/lib/propmangle.js
index ae2a3f44..b20a3815 100644
--- a/lib/propmangle.js
+++ b/lib/propmangle.js
@@ -44,6 +44,12 @@
 "use strict";
 
 function find_builtins() {
+
+    // Compatibility fix for es5.1 and earlier where Symbol isn't defined
+    if (!global.Symbol) {
+        global.Symbol = new Function();
+    }
+
     var a = [];
     [ Object, Array, Function, Number,
       String, Boolean, Error, Math,