diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/collections/Map-clear-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/collections/Map-clear-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+// Clearing an empty Map has no effect.
+
+var m = Map();
+for (var i = 0; i < 2; i++) {
+    m.clear();
+    assertEq(m.size, 0);
+    assertEq(m.has(undefined), false);
+}