diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/ion/bug792944.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/ion/bug792944.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+function whoo() {
+    (new Object()).foo()
+}
+Object.prototype.foo = function() { return undefined };
+whoo();
+Object.prototype.foo = undefined;
+gc();
+try {
+    whoo();
+    assertEq(0, 1);
+} catch(e) {
+    assertEq(e instanceof TypeError, true);
+}