diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/collections/Map-gc-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/collections/Map-gc-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,14 @@
+// Check marking through the values of a Map.
+
+load(libdir + "referencesVia.js");
+
+var m = new Map;
+for (var i = 0; i < 20; i++) {
+    var n = new Map;
+    n.set(i, m);
+    assertEq(referencesVia(n, 'value', m), true);
+    m = n;
+}
+
+gc();
+gc();