diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug794947.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug794947.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,10 @@
+function f(o)
+{
+    print(o instanceof String);
+}
+
+var g = newGlobal();
+f(new Object());
+var o1 = g.eval('new Object()');
+var o2 = Object.create(o1);
+f(o2);