diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testGroupAssignment.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testGroupAssignment.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+assertEq(
+    (function () {
+        var arr = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
+                    17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32 ];
+
+        for (var i = 0; i < 4; ++i) {
+            var src = i * 8;
+            var dst = i * 8 + 7;
+            for (var j = 0; j < 4; ++j) {
+                [arr[dst--], arr[src++]] = [arr[src], arr[dst]];
+            }
+        }
+        return arr;
+    })().toSource(),
+    "[7, 6, 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8, 23, 22, 21, 20, 19, 18, 17, 16, 31, 30, 29, 28, 27, 26, 25, 24, 32]");