diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/arrow-functions/arguments-4.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/arrow-functions/arguments-4.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,14 @@
+// 'arguments' is banned in a function with a rest param,
+// even nested in an arrow-function parameter default value
+
+load(libdir + "asserts.js");
+
+var mistakes = [
+    "(...rest) => arguments",
+    "(...rest) => (x=arguments) => 0",
+    "function f(...rest) { return (x=arguments) => 0; }",
+    "function f(...rest) { return (x=(y=arguments) => 1) => 0; }",
+];
+
+for (var s of mistakes)
+    assertThrowsInstanceOf(function () { eval(s); }, SyntaxError);