--- a/langtools/src/share/classes/com/sun/tools/javah/JavahTask.java	Thu Feb 25 12:26:39 2010 -0800
+++ b/langtools/src/share/classes/com/sun/tools/javah/JavahTask.java	Thu Feb 25 13:32:08 2010 -0800
@@ -255,9 +255,11 @@
         }
 
         this.classes = new ArrayList<String>();
-        for (String classname: classes) {
-            classname.getClass(); // null-check
-            this.classes.add(classname);
+        if (classes != null) {
+            for (String classname: classes) {
+                classname.getClass(); // null-check
+                this.classes.add(classname);
+            }
         }
     }
 
@@ -316,6 +318,12 @@
     int run(String[] args) {
         try {
             handleOptions(args);
+            if (classes == null || classes.size() == 0) {
+                if (help || version || fullVersion)
+                    return 0;
+                else
+                    return 1;
+            }
             boolean ok = run();
             return ok ? 0 : 1;
         } catch (BadArgs e) {
@@ -347,8 +355,7 @@
             fileManager = getDefaultFileManager(diagnosticListener, log);
 
         Iterator<String> iter = args.iterator();
-        if (!iter.hasNext())
-            help = true;
+        boolean noArgs = !iter.hasNext();
 
         while (iter.hasNext()) {
             String arg = iter.next();
@@ -365,7 +372,7 @@
         }
 
         if ((classes == null || classes.size() == 0) &&
-                !(help || version || fullVersion)) {
+                !(noArgs || help || version || fullVersion)) {
             throw new BadArgs("err.no.classes.specified");
         }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javah/T6893943.java	Thu Feb 25 13:32:08 2010 -0800
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2010 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.
+ */
+
+/*
+ * @test
+ * @bug 6893943
+ * @summary exit code from javah with no args is 0
+ */
+
+import java.io.*;
+import java.util.*;
+
+public class T6893943 {
+    public static void main(String... args) throws Exception {
+        new T6893943().run();
+    }
+
+    void run() throws Exception {
+        testSimpleAPI();
+        testCommand();
+    }
+
+    void testSimpleAPI() throws Exception {
+        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.err));
+        int rc = com.sun.tools.javah.Main.run(new String[] { }, pw);
+        expect("testSimpleAPI", rc, 1);
+    }
+
+    void testCommand() throws Exception {
+        File javaHome = new File(System.getProperty("java.home"));
+        if (javaHome.getName().equals("jre"))
+            javaHome = javaHome.getParentFile();
+
+        List<String> command = new ArrayList<String>();
+        command.add(new File(new File(javaHome, "bin"), "javah").getPath());
+        command.add("-J-Xbootclasspath:" + System.getProperty("sun.boot.class.path"));
+        //System.err.println("command: " + command);
+
+        ProcessBuilder pb = new ProcessBuilder(command);
+        pb.redirectErrorStream(true);
+        Process p = pb.start();
+        p.getOutputStream().close();
+        String line;
+        BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
+        while ((line = in.readLine()) != null)
+            System.err.println("javah: " + line);
+        int rc = p.waitFor();
+        expect("testCommand", rc, 1);
+    }
+
+    void expect(String name, int actual, int expect) throws Exception {
+        if (actual != expect)
+            throw new Exception(name + ": unexpected exit: " + actual + ", expected: " + expect);
+    }
+}