diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug699166.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug699166.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,7 @@
+a = "".__proto__
+b = uneval().__proto__
+for (var i = 0; i < 2; i++) {
+    a.__defineSetter__("valueOf", function() {})
+    a + ""
+    delete b.valueOf
+}