diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug787847.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug787847.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,22 @@
+var g = true;
+
+function getown(name)
+{
+    if (g)
+	return { value: 8, enumerable: true, writable: false, configurable: true };
+}
+
+var p = Proxy.create( { getPropertyDescriptor: getown } );
+var o2 = Object.create(p);
+
+function test(x, expected) {
+    for (var i=0; i<3; i++) {
+	var v = x.hello;
+	if (g) assertEq(v, 8);
+    }
+}
+
+g = false
+test(o2);
+g = true;
+test(o2);