--- a/make/build.xml	Mon Nov 03 09:49:52 2014 +0100
+++ b/make/build.xml	Tue Nov 11 16:17:37 2014 +0100
@@ -155,6 +155,7 @@
        <fileset dir="${src.dir}/jdk/nashorn/tools/resources/"/>
     </copy>
     <copy file="${src.dir}/jdk/internal/dynalink/support/messages.properties" todir="${build.classes.dir}/jdk/internal/dynalink/support"/>
+    <copy file="${src.dir}/jdk/nashorn/internal/codegen/anchor.properties" todir="${build.classes.dir}/jdk/nashorn/internal/codegen"/>
 
     <echo message="full=${nashorn.fullversion}" file="${build.classes.dir}/jdk/nashorn/internal/runtime/resources/version.properties"/>
     <echo file="${build.classes.dir}/jdk/nashorn/internal/runtime/resources/version.properties" append="true">${line.separator}</echo>

--- a/src/jdk/nashorn/internal/codegen/OptimisticTypesPersistence.java	Mon Nov 03 09:49:52 2014 +0100
+++ b/src/jdk/nashorn/internal/codegen/OptimisticTypesPersistence.java	Tue Nov 11 16:17:37 2014 +0100
@@ -33,6 +33,8 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -221,11 +223,37 @@
     private static void reportError(final String msg, final File file, final Exception e) {
         final long now = System.currentTimeMillis();
         if(now - lastReportedError > ERROR_REPORT_THRESHOLD) {
-            getLogger().warning(String.format("Failed to %s %s", msg, file), e);
+            reportError(String.format("Failed to %s %s", msg, file), e);
             lastReportedError = now;
         }
     }
 
+    /**
+     * Logs an error message with warning severity (reasoning being that we're reporting an error that'll disable the
+     * type info cache, but it's only logged as a warning because that doesn't prevent Nashorn from running, it just
+     * disables a performance-enhancing cache).
+     * @param msg the message to log
+     * @param e the exception that represents the error.
+     */
+    private static void reportError(final String msg, final Exception e) {
+        getLogger().warning(msg, "\n", exceptionToString(e));
+    }
+
+    /**
+     * A helper that prints an exception stack trace into a string. We have to do this as if we just pass the exception
+     * to {@link DebugLogger#warning(Object...)}, it will only log the exception message and not the stack, making
+     * problems harder to diagnose.
+     * @param e the exception
+     * @return the string representation of {@link Exception#printStackTrace()} output.
+     */
+    private static String exceptionToString(final Exception e) {
+        final StringWriter sw = new StringWriter();
+        final PrintWriter pw = new PrintWriter(sw, false);
+        e.printStackTrace(pw);
+        pw.flush();
+        return sw.toString();
+    }
+
     private static File createBaseCacheDir() {
         if(MAX_FILES == 0 || Options.getBooleanProperty("nashorn.typeInfo.disabled")) {
             return null;
@@ -233,7 +261,7 @@
         try {
             return createBaseCacheDirPrivileged();
         } catch(final Exception e) {
-            getLogger().warning("Failed to create cache dir", e);
+            reportError("Failed to create cache dir", e);
             return null;
         }
     }
@@ -267,7 +295,7 @@
         try {
             return createCacheDirPrivileged(baseDir);
         } catch(final Exception e) {
-            getLogger().warning("Failed to create cache dir", e);
+            reportError("Failed to create cache dir", e);
             return null;
         }
     }
@@ -280,7 +308,7 @@
                 try {
                     versionDirName = getVersionDirName();
                 } catch(final Exception e) {
-                    getLogger().warning("Failed to calculate version dir name", e);
+                    reportError("Failed to calculate version dir name", e);
                     return null;
                 }
                 final File versionDir = new File(baseDir, versionDirName);
@@ -328,7 +356,12 @@
      * @throws Exception if digest could not be created
      */
     public static String getVersionDirName() throws Exception {
-        final URL url = OptimisticTypesPersistence.class.getResource("");
+        // NOTE: getResource("") won't work if the JAR file doesn't have directory entries (and JAR files in JDK distro
+        // don't, or at least it's a bad idea counting on it). Alternatively, we could've tried
+        // getResource("OptimisticTypesPersistence.class") but behavior of getResource with regard to its willingness
+        // to hand out URLs to .class files is also unspecified. Therefore, the most robust way to obtain an URL to our
+        // package is to have a small non-class anchor file and start out from its URL.
+        final URL url = OptimisticTypesPersistence.class.getResource("anchor.properties");
         final String protocol = url.getProtocol();
         if (protocol.equals("jar")) {
             // Normal deployment: nashorn.jar

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk/nashorn/internal/codegen/anchor.properties	Tue Nov 11 16:17:37 2014 +0100
@@ -0,0 +1,27 @@
+#
+# 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+
+# This file exists only so OptimisticTypesPersistence.getVersionDirName() can take its URL.