diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8_5/regress/regress-554955-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8_5/regress/regress-554955-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+function f(s) {
+  eval(s);
+  return function(a) {
+    var d;
+    let (c = 3) {
+      d = function() { a; }; // force Block object to be cloned
+      with({}) {}; // repel JägerMonkey
+      return b; // lookup occurs in scope of Block
+    }
+  };
+}
+
+var b = 1;
+var g1 = f("");
+var g2 = f("var b = 2;");
+
+/* Call the lambda once, caching a reference to the global b. */
+g1(0);
+
+/* 
+ * If this call sees the above cache entry, then it will erroneously use the
+ * global b.
+ */
+assertEq(g2(0), 2);
+
+reportCompare(true, true);