--- a/langtools/src/share/classes/com/sun/tools/javap/JavapFileManager.java	Tue Jul 28 11:00:05 2009 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javap/JavapFileManager.java	Wed Jul 29 13:26:26 2009 -0700
@@ -41,13 +41,13 @@
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
-class JavapFileManager extends JavacFileManager {
+public class JavapFileManager extends JavacFileManager {
     private JavapFileManager(Context context, Charset charset) {
         super(context, true, charset);
         setIgnoreSymbolFile(true);
     }
 
-    static JavapFileManager create(final DiagnosticListener<? super JavaFileObject> dl, PrintWriter log, Options options) {
+    public static JavapFileManager create(final DiagnosticListener<? super JavaFileObject> dl, PrintWriter log) {
         Context javac_context = new Context();
 
         if (dl != null)

--- a/langtools/src/share/classes/com/sun/tools/javap/JavapTask.java	Tue Jul 28 11:00:05 2009 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javap/JavapTask.java	Wed Jul 29 13:26:26 2009 -0700
@@ -316,17 +316,17 @@
             Iterable<String> classes) {
         this(out, fileManager, diagnosticListener);
 
+        this.classes = new ArrayList<String>();
+        for (String classname: classes) {
+            classname.getClass(); // null-check
+            this.classes.add(classname);
+        }
+
         try {
             handleOptions(options, false);
         } catch (BadArgs e) {
             throw new IllegalArgumentException(e.getMessage());
         }
-
-        this.classes = new ArrayList<String>();
-        for (String classname: classes) {
-            classname.getClass(); // null-check
-            this.classes.add(classname);
-        }
     }
 
     public void setLocale(Locale locale) {
@@ -372,10 +372,18 @@
         final PrintWriter pw = getPrintWriterForWriter(w);
         return new DiagnosticListener<JavaFileObject> () {
             public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
-                if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {
+                switch (diagnostic.getKind()) {
+                    case ERROR:
                         pw.print(getMessage("err.prefix"));
-                    pw.print(" ");
+                        break;
+                    case WARNING:
+                        pw.print(getMessage("warn.prefix"));
+                        break;
+                    case NOTE:
+                        pw.print(getMessage("note.prefix"));
+                        break;
                 }
+                pw.print(" ");
                 pw.println(diagnostic.getMessage(null));
             }
         };
@@ -405,7 +413,7 @@
             boolean ok = run();
             return ok ? EXIT_OK : EXIT_ERROR;
         } catch (BadArgs e) {
-            diagnosticListener.report(createDiagnostic(e.key, e.args));
+            reportError(e.key, e.args);
             if (e.showUsage) {
                 log.println(getMessage("main.usage.summary", progname));
             }
@@ -419,7 +427,7 @@
                 e_args[0] = e.getCause();
                 System.arraycopy(e.args, 0, e_args, 1, e.args.length);
             }
-            diagnosticListener.report(createDiagnostic("err.internal.error", e_args));
+            reportError("err.internal.error", e_args);
             return EXIT_ABNORMAL;
         } finally {
             log.flush();
@@ -531,7 +539,7 @@
                         StandardJavaFileManager sfm = (StandardJavaFileManager) fileManager;
                         fo = sfm.getJavaFileObjects(className).iterator().next();
                     } else {
-                       diagnosticListener.report(createDiagnostic("err.not.standard.file.manager", className));
+                       reportError("err.not.standard.file.manager", className);
                        ok = false;
                        continue;
                     }
@@ -547,38 +555,42 @@
                         }
                     }
                     if (fo == null) {
-                       diagnosticListener.report(createDiagnostic("err.class.not.found", className));
+                       reportError("err.class.not.found", className);
                        ok = false;
                        continue;
                     }
                 }
                 attributeFactory.setCompat(options.compat);
                 attributeFactory.setJSR277(options.jsr277);
-
-                write(read(fo));
-
+                ClassFileInfo cfInfo = read(fo);
+                if (!className.endsWith(".class")) {
+                    String cfName = cfInfo.cf.getName();
+                    if (!cfName.replaceAll("[/$]", ".").equals(className.replaceAll("[/$]", ".")))
+                        reportWarning("warn.unexpected.class", className, cfName.replace('/', '.'));
+                }
+                write(cfInfo);
             } catch (ConstantPoolException e) {
-                diagnosticListener.report(createDiagnostic("err.bad.constant.pool", className, e.getLocalizedMessage()));
+                reportError("err.bad.constant.pool", className, e.getLocalizedMessage());
                 ok = false;
             } catch (EOFException e) {
-                diagnosticListener.report(createDiagnostic("err.end.of.file", className));
+                reportError("err.end.of.file", className);
                 ok = false;
             } catch (FileNotFoundException e) {
-                diagnosticListener.report(createDiagnostic("err.file.not.found", e.getLocalizedMessage()));
+                reportError("err.file.not.found", e.getLocalizedMessage());
                 ok = false;
             } catch (IOException e) {
                 //e.printStackTrace();
                 Object msg = e.getLocalizedMessage();
                 if (msg == null)
                     msg = e;
-                diagnosticListener.report(createDiagnostic("err.ioerror", className, msg));
+                reportError("err.ioerror", className, msg);
                 ok = false;
             } catch (Throwable t) {
                 StringWriter sw = new StringWriter();
                 PrintWriter pw = new PrintWriter(sw);
                 t.printStackTrace(pw);
                 pw.close();
-                diagnosticListener.report(createDiagnostic("err.crash", t.toString(), sw.toString()));
+                reportError("err.crash", t.toString(), sw.toString());
                 ok = false;
             }
         }
@@ -684,7 +696,7 @@
     }
 
     private JavaFileManager getDefaultFileManager(final DiagnosticListener<? super JavaFileObject> dl, PrintWriter log) {
-        return JavapFileManager.create(dl, log, options);
+        return JavapFileManager.create(dl, log);
     }
 
     private JavaFileObject getClassFileObject(String className) throws IOException {
@@ -738,10 +750,23 @@
         }
     }
 
-    private Diagnostic<JavaFileObject> createDiagnostic(final String key, final Object... args) {
+    private void reportError(String key, Object... args) {
+        diagnosticListener.report(createDiagnostic(Diagnostic.Kind.ERROR, key, args));
+    }
+
+    private void reportNote(String key, Object... args) {
+        diagnosticListener.report(createDiagnostic(Diagnostic.Kind.NOTE, key, args));
+    }
+
+    private void reportWarning(String key, Object... args) {
+        diagnosticListener.report(createDiagnostic(Diagnostic.Kind.WARNING, key, args));
+    }
+
+    private Diagnostic<JavaFileObject> createDiagnostic(
+            final Diagnostic.Kind kind, final String key, final Object... args) {
         return new Diagnostic<JavaFileObject>() {
             public Kind getKind() {
-                return Diagnostic.Kind.ERROR;
+                return kind;
             }
 
             public JavaFileObject getSource() {
@@ -776,6 +801,10 @@
                 return JavapTask.this.getMessage(locale, key, args);
             }
 
+            public String toString() {
+                return getClass().getName() + "[key=" + key + ",args=" + Arrays.asList(args) + "]";
+            }
+
         };
 
     }

--- a/langtools/src/share/classes/com/sun/tools/javap/resources/javap.properties	Tue Jul 28 11:00:05 2009 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javap/resources/javap.properties	Wed Jul 29 13:26:26 2009 -0700
@@ -24,6 +24,15 @@
 Usage: {0} <options> <classes>\n\
 use -help for a list of possible options
 
+warn.prefix=Warning:
+warn.unexpected.class=Binary file {0} contains {1}
+
+note.prefix=Note:
+
+main.usage.summary=\
+Usage: {0} <options> <classes>\n\
+use -help for a list of possible options
+
 main.usage=\
 Usage: {0} <options> <classes>\n\
 where possible options include:

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javap/T4777949.java	Wed Jul 29 13:26:26 2009 -0700
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+import java.io.*;
+import java.util.*;
+import javax.tools.*;
+import com.sun.tools.javap.*;
+
+/*
+ * @test
+ * @bug 4777949
+ * @summary Warn javap usage on package with simple name
+ */
+public class T4777949 {
+    public static void main(String... args) throws Exception {
+        new T4777949().run();
+    }
+
+    void run() throws Exception {
+        File javaFile = writeTestFile();
+        File classFile = compileTestFile(javaFile);
+
+        test(".", "p.q.r.Test", false);
+        test("p", "q.r.Test", true);
+        test("p/q", "r.Test", true);
+        test("p/q/r", "Test", true);
+        test(".", "p.q.r.Test.Inner", false);
+        test(".", "p.q.r.Test$Inner", false);
+        test("p", "q.r.Test.Inner", true);
+        test("p", "q.r.Test$Inner", true);
+
+        if (errors > 0)
+            throw new Exception(errors + " errors found");
+    }
+
+    void test(String classPath, String className, boolean expectWarnings) {
+        List<Diagnostic<? extends JavaFileObject>> diags =
+            javap(Arrays.asList("-classpath", classPath), Arrays.asList(className));
+        boolean foundWarnings = false;
+        for (Diagnostic<? extends JavaFileObject> d: diags) {
+            if (d.getKind() == Diagnostic.Kind.WARNING)
+                foundWarnings = true;
+        }
+    }
+
+
+    File writeTestFile() throws IOException {
+        File f = new File("Test.java");
+        PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(f)));
+        out.println("package p.q.r;");
+        out.println("class Test { class Inner { } }");
+        out.close();
+        return f;
+    }
+
+    File compileTestFile(File f) {
+        int rc = com.sun.tools.javac.Main.compile(new String[] { "-d", ".", f.getPath() });
+        if (rc != 0)
+            throw new Error("compilation failed. rc=" + rc);
+        String path = f.getPath();
+        return new File(path.substring(0, path.length() - 5) + ".class");
+    }
+
+    List<Diagnostic<? extends JavaFileObject>> javap(List<String> args, List<String> classes) {
+        DiagnosticCollector<JavaFileObject> dc = new DiagnosticCollector<JavaFileObject>();
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        JavaFileManager fm = JavapFileManager.create(dc, pw);
+        JavapTask t = new JavapTask(pw, fm, dc, args, classes);
+        boolean ok = t.run();
+
+        List<Diagnostic<? extends JavaFileObject>> diags = dc.getDiagnostics();
+
+        if (!ok)
+            error("javap failed unexpectedly");
+
+        System.err.println("args=" + args + " classes=" + classes + "\n"
+                           + diags + "\n"
+                           + sw);
+
+        return diags;
+    }
+
+    void error(String msg) {
+        System.err.println("error: " + msg);
+        errors++;
+    }
+
+    int errors;
+}
+