--- a/jdk/src/share/classes/java/awt/Dialog.java	Tue Nov 30 10:35:55 2010 +0300
+++ b/jdk/src/share/classes/java/awt/Dialog.java	Thu Dec 02 15:54:17 2010 +0300
@@ -565,7 +565,7 @@
      * @since 1.6
      */
     public Dialog(Window owner) {
-        this(owner, null, ModalityType.MODELESS);
+        this(owner, "", ModalityType.MODELESS);
     }
 
     /**
@@ -624,7 +624,7 @@
      * @since 1.6
      */
     public Dialog(Window owner, ModalityType modalityType) {
-        this(owner, null, modalityType);
+        this(owner, "", modalityType);
     }
 
     /**

--- a/jdk/src/share/classes/javax/swing/JDialog.java	Tue Nov 30 10:35:55 2010 +0300
+++ b/jdk/src/share/classes/javax/swing/JDialog.java	Thu Dec 02 15:54:17 2010 +0300
@@ -154,8 +154,8 @@
     }
 
     /**
-     * Creates a modeless dialog without a title with the
-     * specified {@code Frame} as its owner.  If {@code owner}
+     * Creates a modeless dialog with the specified {@code Frame}
+     * as its owner and an empty title. If {@code owner}
      * is {@code null}, a shared, hidden frame will be set as the
      * owner of the dialog.
      * <p>
@@ -179,8 +179,8 @@
     }
 
     /**
-     * Creates a dialog with the specified owner {@code Frame}, modality
-     * and an empty title. If {@code owner} is {@code null},
+     * Creates a dialog with an empty title and the specified modality and
+     * {@code Frame} as its owner. If {@code owner} is {@code null},
      * a shared, hidden frame will be set as the owner of the dialog.
      * <p>
      * This constructor sets the component's locale property to the value
@@ -202,7 +202,7 @@
      * @see JComponent#getDefaultLocale
      */
     public JDialog(Frame owner, boolean modal) {
-        this(owner, null, modal);
+        this(owner, "", modal);
     }
 
     /**
@@ -330,8 +330,8 @@
     }
 
     /**
-     * Creates a modeless dialog without a title with the
-     * specified {@code Dialog} as its owner.
+     * Creates a modeless dialog with the specified {@code Dialog}
+     * as its owner and an empty title.
      * <p>
      * This constructor sets the component's locale property to the value
      * returned by {@code JComponent.getDefaultLocale}.
@@ -348,7 +348,8 @@
     }
 
     /**
-     * Creates a dialog with the specified owner {@code Dialog} and modality.
+     * Creates a dialog with an empty title and the specified modality and
+     * {@code Dialog} as its owner.
      * <p>
      * This constructor sets the component's locale property to the value
      * returned by {@code JComponent.getDefaultLocale}.
@@ -369,7 +370,7 @@
      * @see JComponent#getDefaultLocale
      */
     public JDialog(Dialog owner, boolean modal) {
-        this(owner, null, modal);
+        this(owner, "", modal);
     }
 
     /**
@@ -461,8 +462,8 @@
     }
 
     /**
-     * Creates a modeless dialog with the specified owner {@code Window} and
-     * an empty title.
+     * Creates a modeless dialog with the specified {@code Window}
+     * as its owner and an empty title.
      * <p>
      * This constructor sets the component's locale property to the value
      * returned by {@code JComponent.getDefaultLocale}.
@@ -488,8 +489,8 @@
     }
 
     /**
-     * Creates a dialog with the specified owner {@code Window}, modality
-     * and an empty title.
+     * Creates a dialog with an empty title and the specified modality and
+     * {@code Window} as its owner.
      * <p>
      * This constructor sets the component's locale property to the value
      * returned by {@code JComponent.getDefaultLocale}.
@@ -520,7 +521,7 @@
      * @since 1.6
      */
     public JDialog(Window owner, ModalityType modalityType) {
-        this(owner, null, modalityType);
+        this(owner, "", modalityType);
     }
 
     /**

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/swing/JDialog/6639507/bug6639507.java	Thu Dec 02 15:54:17 2010 +0300
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2010, 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 6639507
+   @summary Title of javax.swing.JDialog is null while spec says it's empty
+   @author Pavel Porvatov
+*/
+import javax.swing.*;
+import java.awt.*;
+
+public class bug6639507 {
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(new Runnable() {
+            public void run() {
+                assertEmptyTitle(new Dialog((Frame) null), "new Dialog((Frame) null)");
+                assertEmptyTitle(new Dialog((Frame) null, true), "new Dialog((Frame) null, true)");
+                assertEmptyTitle(new Dialog((Dialog) null), "new Dialog((Dialog) null)");
+                assertEmptyTitle(new Dialog((Window) null), "new Dialog((Window) null)");
+                assertEmptyTitle(new Dialog(new Dialog((Window) null), Dialog.ModalityType.APPLICATION_MODAL),
+                        "new Dialog((Window) null), Dialog.ModalityType.APPLICATION_MODAL");
+
+                assertEmptyTitle(new JDialog((Frame) null), "new JDialog((Frame) null)");
+                assertEmptyTitle(new JDialog((Frame) null, true), "new JDialog((Frame) null, true)");
+                assertEmptyTitle(new JDialog((Dialog) null), "new JDialog((Dialog) null)");
+                assertEmptyTitle(new JDialog((Dialog) null, true), "new JDialog((Dialog) null, true)");
+                assertEmptyTitle(new JDialog((Window) null), "new JDialog((Window) null)");
+                assertEmptyTitle(new JDialog((Window) null, Dialog.ModalityType.APPLICATION_MODAL),
+                        "new JDialog((Window) null, Dialog.ModalityType.APPLICATION_MODAL)");
+            }
+        });
+    }
+
+    private static void assertEmptyTitle(Dialog dialog, String ctr) {
+        String title = dialog.getTitle();
+
+        if (title == null || title.length() > 0) {
+            throw new RuntimeException("Title is not empty for constructor " + ctr);
+        }
+    }
+}