diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testBug663789-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testBug663789-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,6 @@
+// |jit-test| debug
+
+o = { toString:function() { return evalInFrame(1, "x") } }
+var x = 'C';
+var s = "aaaaaaaaaa".replace(/a/g, function() { var x = 'B'; return o });
+assertEq(s, "CCCCCCCCCC");