diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug673468.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug673468.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+var g = newGlobal();
+var k = g.eval('var u = new Object(); u');
+var m = new WeakMap();
+m.set(k, {});
+k = null;
+gc();
+k = g.eval('u');
+assertEq(m.has(k), true);