diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug643243.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug643243.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+{
+    function newSandbox(n) {}
+}
+var o12 = Float32Array.prototype;
+function f12(o) {
+    eval('o')['__proto_' + '_'] = null;
+}
+for (var i = 0; i < 14; i++) {
+    gc()
+    new f12(o12);
+}