diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/auto-regress/bug523793.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/auto-regress/bug523793.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+// |jit-test| error:ReferenceError
+
+// Binary: cache/js-dbg-32-525d852c622d-linux
+// Flags: -j
+//
+(function() {
+    let(x)
+    (function() {
+        for (let a in [0, x, 0, 0])
+        (function() {
+            for (let y in [0, 0]) print
+        })();
+    })()
+    with({}) throw x;
+})()