--- a/nashorn/src/jdk/nashorn/internal/objects/NativeString.java	Wed May 29 14:08:00 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/objects/NativeString.java	Wed May 29 21:27:10 2013 +0530
@@ -631,17 +631,24 @@
 
         final String str       = checkObjectToString(self);
         final String searchStr = JSType.toString(search);
+        final int length       = str.length();
 
-        int from;
+        int end;
 
         if (pos == UNDEFINED) {
-            from = str.length();
+            end = length;
         } else {
             final double numPos = JSType.toNumber(pos);
-            from = !Double.isNaN(numPos) ? (int)numPos : (int)Double.POSITIVE_INFINITY;
+            end = Double.isNaN(numPos) ? length : (int)numPos;
+            if (end < 0) {
+                end = 0;
+            } else if (end > length) {
+                end = length;
+            }
         }
 
-        return str.lastIndexOf(searchStr, from);
+
+        return str.lastIndexOf(searchStr, end);
     }
 
     /**

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8015349.js	Wed May 29 21:27:10 2013 +0530
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ * 
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ * 
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ * 
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ * 
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8015349: "abc".lastIndexOf("a",-1) should evaluate to 0 and not -1
+ *
+ * @test
+ * @run
+ */
+
+function printEval(code) {
+    print(code + " = " + eval(code));
+}
+
+printEval("'abc'.lastIndexOf('a', 4)"); 
+printEval("'abc'.lastIndexOf('b', Infinity)");
+printEval("'abc'.lastIndexOf('a', -1)");
+printEval("'abc'.lastIndexOf('a', -Infinity)");
+printEval("'oracle'.lastIndexOf('u')");
+printEval("'hello'.lastIndexOf('l')");
+printEval("'hello'.lastIndexOf('l', 2)");
+printEval("'hello'.lastIndexOf('l', 3)");
+printEval("'hello'.lastIndexOf('l', 1)");

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8015349.js.EXPECTED	Wed May 29 21:27:10 2013 +0530
@@ -0,0 +1,9 @@
+'abc'.lastIndexOf('a', 4) = 0
+'abc'.lastIndexOf('b', Infinity) = 1
+'abc'.lastIndexOf('a', -1) = 0
+'abc'.lastIndexOf('a', -Infinity) = 0
+'oracle'.lastIndexOf('u') = -1
+'hello'.lastIndexOf('l') = 3
+'hello'.lastIndexOf('l', 2) = 2
+'hello'.lastIndexOf('l', 3) = 3
+'hello'.lastIndexOf('l', 1) = -1