--- a/jdk/src/java.base/share/classes/sun/util/locale/LocaleMatcher.java	Mon Jun 13 21:49:37 2016 +0000
+++ b/jdk/src/java.base/share/classes/sun/util/locale/LocaleMatcher.java	Tue Jun 14 12:29:49 2016 +0900
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2016, 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
@@ -228,7 +228,8 @@
                     rangeForRegex = rangeForRegex.substring(0, index);
 
                     // if range ends with an extension key, truncate it.
-                    if (rangeForRegex.lastIndexOf('-') == rangeForRegex.length()-2) {
+                    index = rangeForRegex.lastIndexOf('-');
+                    if (index >= 0 && index == rangeForRegex.length()-2) {
                         rangeForRegex =
                             rangeForRegex.substring(0, rangeForRegex.length()-2);
                     }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/Locale/Bug8135061.java	Tue Jun 14 12:29:49 2016 +0900
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+/*
+ * @test
+ * @bug 8135061
+ * @summary Checks that the Locale.lookup executes properly without throwing
+ *          any exception for some specific language ranges
+ * @run main Bug8135061
+ */
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+import java.util.Locale.LanguageRange;
+
+public class Bug8135061 {
+
+    public static void main(String[] args) {
+
+        /* lookup should run without throwing any exception and
+         * return null as the language range does not match with the language
+         * tag
+         */
+        List<LanguageRange> ranges = LanguageRange.parse("nv");
+        Collection<Locale> locales = Collections.singleton(Locale.ENGLISH);
+
+        try {
+            Locale match = Locale.lookup(ranges, locales);
+            if (match != null) {
+                throw new RuntimeException("Locale.lookup returned non-null: "
+                        + match);
+            }
+        } catch (Exception ex) {
+            throw new RuntimeException("[Locale.lookup failed on language"
+                    + " range: " + ranges + " and language tags "
+                    + locales + "]", ex);
+        }
+
+        /* lookup should run without throwing any exception and
+         * return "nv" as the matching tag
+         */
+        ranges = LanguageRange.parse("i-navajo");
+        locales = Collections.singleton(new Locale("nv"));
+
+        try {
+            Locale match = Locale.lookup(ranges, locales);
+            if (!match.toLanguageTag().equals("nv")) {
+                throw new RuntimeException("Locale.lookup returned unexpected"
+                        + " result: " + match);
+            }
+        } catch (Exception ex) {
+            throw new RuntimeException("[Locale.lookup failed on language"
+                    + " range: " + ranges + " and language tags "
+                    + locales + "]", ex);
+        }
+
+    }
+
+}