--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jdeps/share/classes/com/sun/tools/jdeps/VersionHelper.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,75 @@
+/*
+ * 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.  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.
+ */
+
+package com.sun.tools.jdeps;
+
+import com.sun.tools.classfile.ClassFile;
+import com.sun.tools.classfile.ConstantPoolException;
+import jdk.internal.misc.SharedSecrets;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+public class VersionHelper {
+    private static final String META_INF_VERSIONS = "META-INF/versions/";
+    private static final Map<String,String> nameToVersion = new ConcurrentHashMap<>();
+
+    public static String get(String classname) {
+        if (nameToVersion.containsKey(classname)) {
+            return nameToVersion.get(classname) + "/" + classname;
+        }
+        return classname;
+    }
+
+    public static void add(JarFile jarfile, JarEntry e, ClassFile cf)
+            throws ConstantPoolException
+    {
+        String realName = SharedSecrets.javaUtilJarAccess().getRealName(jarfile, e);
+        if (realName.startsWith(META_INF_VERSIONS)) {
+            int len = META_INF_VERSIONS.length();
+            int n = realName.indexOf('/', len);
+            if (n > 0) {
+                String version = realName.substring(len, n);
+                assert (Integer.parseInt(version) > 8);
+                String name = cf.getName().replace('/', '.');
+                if (nameToVersion.containsKey(name)) {
+                    if (!version.equals(nameToVersion.get(name))) {
+                        throw new MultiReleaseException(
+                                "err.multirelease.version.associated",
+                                name, nameToVersion.get(name), version
+                        );
+                    }
+                } else {
+                    nameToVersion.put(name, version);
+                }
+            } else {
+                throw new MultiReleaseException("err.multirelease.jar.malformed",
+                        jarfile.getName(), realName);
+            }
+        }
+    }
+}