diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_6/Map/forEach-selfhosted-behavior.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_6/Map/forEach-selfhosted-behavior.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,51 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 987243;
+var summary = "Don't use .call(...) in the self-hosted Map.prototype.forEach";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+var functionCall = Function.prototype.call;
+
+function throwSyntaxError()
+{
+  throw new SyntaxError("Function.prototype.call incorrectly called");
+}
+
+function lalala() {}
+
+Function.prototype.call = throwSyntaxError;
+
+new Map().forEach(throwSyntaxError);
+new Map([[1, 2]]).forEach(lalala);
+new Map([[1, 2], [3, 4]]).forEach(lalala);
+
+Function.prototype.call = function() { this.set(42, "fnord"); };
+
+new Map().forEach(throwSyntaxError);
+new Map([[1, 2]]).forEach(lalala);
+new Map([[1, 2], [3, 4]]).forEach(lalala);
+
+var callCount = 0;
+Function.prototype.call = function() { callCount++; };
+
+new Map().forEach(throwSyntaxError);
+new Map([[1, 2]]).forEach(lalala);
+new Map([[1, 2], [3, 4]]).forEach(lalala);
+
+assertEq(callCount, 0);
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");