diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/extensions/String-methods-infinite-recursion.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/extensions/String-methods-infinite-recursion.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 657585;
+var summary =
+  'Guard against infinite recursion when converting |this| to string for the ' +
+  'String.prototype.* methods';
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+try
+{
+  var obj = {};
+  obj.toString = String.prototype.charAt;
+  "" + obj;
+  throw new Error("should have thrown");
+}
+catch (e)
+{
+  assertEq(e instanceof InternalError, true,
+           "should have thrown InternalError for over-recursion, got: " + e);
+}
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("All tests passed!");