--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ECMAException.java	Fri Oct 31 10:06:52 2014 +0100
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ECMAException.java	Fri Oct 31 16:50:31 2014 +0100
@@ -96,15 +96,17 @@
         // If thrown object is an Error or sub-object like TypeError, then
         // an ECMAException object has been already initialized at constructor.
         if (thrown instanceof ScriptObject) {
-            final ScriptObject sobj = (ScriptObject)thrown;
-            final Object exception = getException(sobj);
+            final Object exception = getException((ScriptObject)thrown);
             if (exception instanceof ECMAException) {
-                // copy over file name, line number and column number.
                 final ECMAException ee = (ECMAException)exception;
-                ee.setFileName(fileName);
-                ee.setLineNumber(line);
-                ee.setColumnNumber(column);
-                return ee;
+                // Make sure exception has correct thrown reference because that's what will end up getting caught.
+                if (ee.getThrown() == thrown) {
+                    // copy over file name, line number and column number.
+                    ee.setFileName(fileName);
+                    ee.setLineNumber(line);
+                    ee.setColumnNumber(column);
+                    return ee;
+                }
             }
         }
 
@@ -154,7 +156,11 @@
      * @return a {@link ECMAException}
      */
     public static Object getException(final ScriptObject errObj) {
-        return errObj.get(ECMAException.EXCEPTION_PROPERTY);
+        // Exclude inherited properties that may belong to errors in the prototype chain.
+        if (errObj.hasOwnProperty(ECMAException.EXCEPTION_PROPERTY)) {
+            return errObj.get(ECMAException.EXCEPTION_PROPERTY);
+        }
+        return null;
     }
 
     /**

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8062583.js	Fri Oct 31 16:50:31 2014 +0100
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2014, 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-8062583: Throwing object with error prototype causes error proto to be caught
+ *
+ * @test
+ * @run
+ */
+
+function CustomError() {
+    this.name = "CustomError";
+}
+
+CustomError.prototype = new Error();
+
+var c1 = new CustomError();
+
+try {
+    throw c1;
+} catch (e) {
+    print(e === c1);
+    print(e === CustomError.prototype);
+    print(e.stack.replace(/\\/g, '/'));
+    print(e.nashornException.toString().replace(/\\/g, '/'));
+}
+
+var c2 = new CustomError();
+Error.captureStackTrace(c2);
+print(c2.stack.replace(/\\/g, '/'));
+print(c2.nashornException.toString().replace(/\\/g, '/'));

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8062583.js.EXPECTED	Fri Oct 31 16:50:31 2014 +0100
@@ -0,0 +1,8 @@
+true
+false
+CustomError
+	at <program> (test/script/basic/JDK-8062583.js:40)
+test/script/basic/JDK-8062583.js:40:4 CustomError
+CustomError
+	at <program> (test/script/basic/JDK-8062583.js:49)
+test/script/basic/JDK-8062583.js:49 CustomError