diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/arguments/defaults-invalid-syntax.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/arguments/defaults-invalid-syntax.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+load(libdir + "asserts.js");
+
+assertThrowsInstanceOf(function () {
+    eval("function f(...rest=23) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f([a]=4) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a=4, [b]) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a=yield 24) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a={a : 19 + (yield 24).prop}) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a=1,a=1) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a,a=1) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a=1,a) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a,a,b=1) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a,b=1,a=1) {}");
+}, SyntaxError);
+assertThrowsInstanceOf(function () {
+    eval("function f(a=1,b=1,a=1) {}");
+}, SyntaxError);
+function silly_but_okay(a=(function () { yield 97; })) {}