diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8_5/extensions/regress-697515.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8_5/extensions/regress-697515.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,6 @@
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+assertEq(new WeakMap().set({}, 0), undefined);
+
+reportCompare(0, 0, 'ok');