diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_5/String/regress-107771.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_5/String/regress-107771.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,91 @@
+/* -*- 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: 31 October 2001
+ *
+ * SUMMARY: Regression test for bug 107771
+ * See http://bugzilla.mozilla.org/show_bug.cgi?id=107771
+ *
+ * The bug: Section 1 passed, but Sections 2-5 all failed with |actual| == 12
+ */
+//-----------------------------------------------------------------------------
+var UBound = 0;
+var BUGNUMBER = 107771;
+var summary = "Regression test for bug 107771";
+var status = '';
+var statusitems = [];
+var actual = '';
+var actualvalues = [];
+var expect= '';
+var expectedvalues = [];
+var str = '';
+var k = -9999;
+
+
+status = inSection(1);
+str = "AAA//BBB/CCC/";
+k = str.lastIndexOf('/');
+actual = k;
+expect = 12;
+
+status = inSection(2);
+str = str.substring(0, k);
+k = str.lastIndexOf('/');
+actual = k;
+expect = 8;
+addThis();
+
+status = inSection(3);
+str = str.substring(0, k);
+k = str.lastIndexOf('/');
+actual = k;
+expect = 4;
+addThis();
+
+status = inSection(4);
+str = str.substring(0, k);
+k = str.lastIndexOf('/');
+actual = k;
+expect = 3;
+addThis();
+
+status = inSection(5);
+str = str.substring(0, k);
+k = str.lastIndexOf('/');
+actual = k;
+expect = -1;
+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');
+}