diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/new-read-before-write.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/new-read-before-write.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,24 @@
+
+function Foo() {
+  var x = this.property;
+  this.property = 5;
+  glob = x;
+}
+Foo.prototype.property = 10;
+for (var i = 0; i < 10; i++) {
+  new Foo();
+  assertEq(glob, 10);
+}
+
+function Bar() {
+  this.property;
+  this.other = 5;
+}
+Bar.prototype.other = 10;
+Object.defineProperty(Bar.prototype, "property", {
+  get: function() { glob = this.other; }
+});
+for (var i = 0; i < 10; i++) {
+  new Bar();
+  assertEq(glob, 10);
+}