--- a/langtools/src/share/classes/com/sun/tools/javadoc/SerialFieldTagImpl.java	Thu Jun 30 14:33:45 2011 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javadoc/SerialFieldTagImpl.java	Fri Jul 01 13:34:37 2011 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2011, 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
@@ -80,6 +80,9 @@
      */
     private void parseSerialFieldString() {
         int len = text.length();
+        if (len == 0) {
+            return;
+        }
 
         // if no white space found
         /* Skip white space. */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/com/sun/javadoc/T6735320/SerialFieldTest.java	Fri Jul 01 13:34:37 2011 -0700
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2011, 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.
+ */
+import java.io.ObjectStreamField;
+import java.io.Serializable;
+
+public class SerialFieldTest implements Serializable {
+    /**
+     * @serialField
+     */
+    private static final ObjectStreamField[] serialPersistentFields = {
+        new ObjectStreamField("i", int.class),
+    };
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/com/sun/javadoc/T6735320/T6735320.java	Fri Jul 01 13:34:37 2011 -0700
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2011, 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 6735320
+ * @summary javadoc throws exception if serialField value is missing
+ * @library  ../lib/
+ * @build    JavadocTester T6735320
+ * @run main T6735320
+ */
+public class T6735320 extends JavadocTester {
+
+    private static final String BUG_ID = "6735320";
+    private static final String[] ARGS = new String[]{
+        "-d", BUG_ID + ".out",
+        SRC_DIR + FS + "SerialFieldTest.java"
+    };
+
+    public String getBugId() {
+        return BUG_ID;
+    }
+
+    public String getBugName() {
+        return getClass().getName();
+    }
+
+    public static void main(String... args) {
+        T6735320 tester = new T6735320();
+        if (tester.runJavadoc(ARGS) != 0) {
+            throw new AssertionError("non-zero return code from javadoc");
+        }
+        if (tester.getErrorOutput().contains("StringIndexOutOfBoundsException")) {
+            throw new AssertionError("javadoc threw StringIndexOutOfBoundsException");
+        }
+    }
+}

--- a/langtools/test/com/sun/javadoc/lib/JavadocTester.java	Thu Jun 30 14:33:45 2011 -0700
+++ b/langtools/test/com/sun/javadoc/lib/JavadocTester.java	Fri Jul 01 13:34:37 2011 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2009, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2011, 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
@@ -197,8 +197,13 @@
         initOutputBuffers();
 
         ByteArrayOutputStream stdout = new ByteArrayOutputStream();
-        PrintStream prev = System.out;
+        PrintStream prevOut = System.out;
         System.setOut(new PrintStream(stdout));
+
+        ByteArrayOutputStream stderr = new ByteArrayOutputStream();
+        PrintStream prevErr = System.err;
+        System.setErr(new PrintStream(stderr));
+
         int returnCode = com.sun.tools.javadoc.Main.execute(
                 getBugName(),
                 new PrintWriter(errors, true),
@@ -207,8 +212,11 @@
                 docletClass,
                 getClass().getClassLoader(),
                 args);
-        System.setOut(prev);
+        System.setOut(prevOut);
         standardOut = new StringBuffer(stdout.toString());
+        System.setErr(prevErr);
+        errors.write(NL + stderr.toString());
+
         printJavadocOutput();
         return returnCode;
     }