diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_3/RegExp/regress-28686.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_3/RegExp/regress-28686.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+test();
+
+function test()
+{   
+  enterFunc ("test");
+
+  printBugNumber (28686);
+   
+  var str = 'foo "bar" baz';
+  reportCompare ('foo \\"bar\\" baz', str.replace(/([\'\"])/g, "\\$1"),
+		 "str.replace failed.");
+   
+  exitFunc ("test");
+   
+}