diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/collections/key-equality-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/collections/key-equality-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+// Number keys are distinct from string keys that would name the same property.
+
+var s = new Set;
+
+s.add(17);
+assertEq(s.has("17"), false);
+assertEq(s.has(17), true);
+s.add("17");
+assertEq(s.delete(17), true);
+assertEq(s.has("17"), true);
+assertEq(s.has(17), false);