diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/Date/equality-to-boolean.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/Date/equality-to-boolean.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,39 @@
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+//-----------------------------------------------------------------------------
+print("Test for correct implementation of |Date == boolean| and vice versa");
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+Date.prototype.toString = function() { return 1; };
+Date.prototype.valueOf = function() { return 0; };
+
+/*
+ * ES5 11.9.3 doesn't directly handle obj == boolean.  Instead it translates it
+ * as follows:
+ *
+ *   obj == boolean
+ *   ↳ obj == ToNumber(boolean), per step 7
+ *     ↳ ToPrimitive(obj) == ToNumber(boolean), per step 9
+ *
+ * ToPrimitive calls [[DefaultValue]] with no hint.  For Date objects this is
+ * treated as if it were instead called with hint String.  That calls toString,
+ * which returns 1, so Date objects here should compare equal to true and
+ * unequal to false.
+ */
+assertEq(new Date == true, true);
+assertEq(new Date == false, false);
+
+/* == is symmetric. */
+assertEq(true == new Date, true);
+assertEq(false == new Date, false);
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");