diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug618350.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug618350.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,24 @@
+
+var global = 0;
+
+Object.defineProperty(Object.prototype, 0, {set: function() { global++; }});
+
+for (var x = 0; x < 20; ++x)
+  [1,2];
+assertEq(global, 0);
+
+Object.defineProperty(Object.prototype, 1, {set: function() { global++; }});
+
+for (var x = 0; x < 20; ++x)
+  [1,2];
+assertEq(global, 0);
+
+Object.defineProperty(Object.prototype, "b", {set: function() { global++; }});
+
+for (var x = 0; x < 20; ++x) {
+  var s = { a:0, b:1, 0: 2, 1: 3 };
+}
+assertEq(global, 0);
+
+assertEq([42][0], 42);
+assertEq([42].length, 1);