diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug836563.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug836563.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,5 @@
+
+var x = {};
+Object.defineProperty(x, 0, { configurable: true, value: null });
+x.p = 0
+Object.defineProperty(x, 0, { value: 2 });