diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_5/Regress/regress-31255.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_5/Regress/regress-31255.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ *
+ * Date:    09 November 2002
+ * SUMMARY: JS should treat --> as a single-line comment indicator.
+ *          Whitespace may occur before the --> on the same line.
+ *
+ * See http://bugzilla.mozilla.org/show_bug.cgi?id=31255
+ * and http://bugzilla.mozilla.org/show_bug.cgi?id=179366 (Rhino version)
+ *
+ * Note: <!--, --> are the HTML multi-line comment opener, closer.
+ * JS already accepted <!-- as a single-line comment indicator.
+ *
+ */
+//-----------------------------------------------------------------------------
+var UBound = 0;
+var BUGNUMBER = 31255;
+var summary = 'JS should treat --> as a single-line comment indicator';
+var status = '';
+var statusitems = [];
+var actual = '';
+var actualvalues = [];
+var expect= '';
+var expectedvalues = [];
+
+
+<!-- HTML comment start is already a single-line JS comment indicator
+ var x = 1; <!-- until end-of-line
+
+	     status = inSection(1);
+actual = (x == 1);
+expect = true;
+addThis();
+
+--> HTML comment end is JS comments until end-of-line
+--> but only if it follows a possible whitespace after line start
+--> so in the following --> should not be treated as comments
+if (x-->0)
+  x = 2;
+
+status = inSection(2);
+actual = (x == 2);
+expect = true;
+addThis();
+
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+
+
+function addThis()
+{
+  statusitems[UBound] = status;
+  actualvalues[UBound] = actual;
+  expectedvalues[UBound] = expect;
+  UBound++;
+}
+
+
+function test()
+{
+  enterFunc('test');
+  printBugNumber(BUGNUMBER);
+  printStatus(summary);
+
+  for (var i=0; i<UBound; i++)
+  {
+    reportCompare(expectedvalues[i], actualvalues[i], statusitems[i]);
+  }
+
+  exitFunc ('test');
+}