diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8_5/extensions/regress-672804-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8_5/extensions/regress-672804-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+// |reftest| require-or(debugMode,skip)
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+var a = 0;
+function f() {
+    let (a = let (x = 1) x) {}
+}
+
+trap(f, 4, 'assertEq(evalInFrame(1, "a"), 0)');
+f();
+
+reportCompare(0, 0, 'ok');