--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/PathFileObject.java	Thu Apr 20 14:37:15 2017 -0700
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/PathFileObject.java	Thu Apr 20 16:13:40 2017 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2017, 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
@@ -150,6 +150,7 @@
      * @param fileManager the file manager creating this file object
      * @param path the path referred to by this file object
      * @param userJarPath the path of the jar file containing the file system.
+     * @return the file object
      */
     public static PathFileObject forJarPath(BaseFileManager fileManager,
             Path path, Path userJarPath) {
@@ -220,6 +221,7 @@
      *
      * @param fileManager the file manager creating this file object
      * @param path the path referred to by this file object
+     * @return the file object
      */
     public static PathFileObject forJRTPath(BaseFileManager fileManager,
             final Path path) {
@@ -304,6 +306,16 @@
             return null;
         }
 
+        @Override @DefinedBy(Api.COMPILER)
+        public Kind getKind() {
+            return BaseFileManager.getKind(userPath);
+        }
+
+        @Override @DefinedBy(Api.COMPILER)
+        public boolean isNameCompatible(String simpleName, Kind kind) {
+            return isPathNameCompatible(userPath, simpleName, kind);
+        }
+
         @Override
         PathFileObject getSibling(String baseName) {
             return new SimpleFileObject(fileManager,
@@ -369,34 +381,37 @@
 
     @Override @DefinedBy(Api.COMPILER)
     public Kind getKind() {
-        return BaseFileManager.getKind(path.getFileName().toString());
+        return BaseFileManager.getKind(path);
     }
 
     @Override @DefinedBy(Api.COMPILER)
     public boolean isNameCompatible(String simpleName, Kind kind) {
+        return isPathNameCompatible(path, simpleName, kind);
+    }
+
+    protected boolean isPathNameCompatible(Path p, String simpleName, Kind kind) {
         Objects.requireNonNull(simpleName);
         Objects.requireNonNull(kind);
 
-        if (kind == Kind.OTHER && getKind() != kind) {
+        if (kind == Kind.OTHER && BaseFileManager.getKind(p) != kind) {
             return false;
         }
 
         String sn = simpleName + kind.extension;
-        String pn = path.getFileName().toString();
+        String pn = p.getFileName().toString();
         if (pn.equals(sn)) {
             return true;
         }
 
-        if (path.getFileSystem() == defaultFileSystem) {
+        if (p.getFileSystem() == defaultFileSystem) {
             if (isMacOS) {
-                String name = path.getFileName().toString();
-                if (Normalizer.isNormalized(name, Normalizer.Form.NFD)
+                if (Normalizer.isNormalized(pn, Normalizer.Form.NFD)
                         && Normalizer.isNormalized(sn, Normalizer.Form.NFC)) {
                     // On Mac OS X it is quite possible to have the file name and the
                     // given simple name normalized in different ways.
                     // In that case we have to normalize file name to the
                     // Normal Form Composed (NFC).
-                    String normName = Normalizer.normalize(name, Normalizer.Form.NFC);
+                    String normName = Normalizer.normalize(pn, Normalizer.Form.NFC);
                     if (normName.equals(sn)) {
                         return true;
                     }
@@ -406,7 +421,7 @@
             if (pn.equalsIgnoreCase(sn)) {
                 try {
                     // allow for Windows
-                    return path.toRealPath(LinkOption.NOFOLLOW_LINKS).getFileName().toString().equals(sn);
+                    return p.toRealPath(LinkOption.NOFOLLOW_LINKS).getFileName().toString().equals(sn);
                 } catch (IOException e) {
                 }
             }
@@ -552,9 +567,12 @@
         return (lastDot == -1 ? fileName : fileName.substring(0, lastDot));
     }
 
-    /** Return the last component of a presumed hierarchical URI.
-     *  From the scheme specific part of the URI, it returns the substring
-     *  after the last "/" if any, or everything if no "/" is found.
+    /**
+     * Return the last component of a presumed hierarchical URI.
+     * From the scheme specific part of the URI, it returns the substring
+     * after the last "/" if any, or everything if no "/" is found.
+     * @param fo the file object
+     * @return the simple name of the file object
      */
     public static String getSimpleName(FileObject fo) {
         URI uri = fo.toUri();

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/file/SymLinkTest.java	Thu Apr 20 16:13:40 2017 -0700
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2014, 2017, 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 8178017
+ * @summary JDK 9 change to symlink handling causes misleading
+ *      class.public.should.be.in.file diagnostic
+ * @library /tools/lib
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.main
+ * @build toolbox.JavacTask toolbox.TestRunner toolbox.ToolBox
+ * @run main SymLinkTest
+ */
+
+import java.io.IOException;
+import java.nio.file.FileSystemException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import toolbox.JavacTask;
+import toolbox.TestRunner;
+import toolbox.TestRunner.Test;
+import toolbox.ToolBox;
+
+public class SymLinkTest extends TestRunner {
+    public static void main(String... args) throws Exception {
+        new SymLinkTest().runTests(m -> new Object[] { Paths.get(m.getName()) });
+    }
+
+    private final ToolBox tb = new ToolBox();
+
+    public SymLinkTest() {
+        super(System.err);
+    }
+
+    @Test
+    public void testgetKind(Path base) throws IOException {
+        test(base, "SOURCE");
+    }
+
+    @Test
+    public void testSymLink(Path base) throws IOException {
+        test(base, "SOURCE.java");
+    }
+
+    void test(Path base, String name) throws IOException {
+        Path file = base.resolve(name);
+        Path javaFile = base.resolve("HelloWorld.java");
+        tb.writeFile(file,
+                "public class HelloWorld {\n"
+                + "    public static void main(String... args) {\n"
+                + "        System.err.println(\"Hello World!\");\n"
+                + "    }\n"
+                + "}");
+
+        try {
+            Files.createSymbolicLink(javaFile, file.getFileName());
+        } catch (FileSystemException fse) {
+            System.err.println("warning: test passes vacuously, sym-link could not be created");
+            System.err.println(fse.getMessage());
+            return;
+        }
+
+        Path classes = Files.createDirectories(base.resolve("classes"));
+        new JavacTask(tb)
+            .outdir(classes)
+            .files(javaFile)
+            .run()
+            .writeAll();
+    }
+}
+