diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/arrow-functions/associativity-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/arrow-functions/associativity-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+// Arrow right-associativity with =
+
+var a, b, c;
+a = b = c => a = b = c;
+assertEq(a, b);
+a(13);
+assertEq(b, 13);
+assertEq(a, 13);