--- a/src/java.desktop/share/classes/javax/swing/GroupLayout.java	Fri Apr 03 10:41:34 2015 -0700
+++ b/src/java.desktop/share/classes/javax/swing/GroupLayout.java	Mon Apr 06 18:16:22 2015 +0400
@@ -2190,7 +2190,7 @@
                     }
                 } else {
                     // Not a padding spring
-                    if (newLeading.size() > 0 && insert) {
+                    if (newLeading.size() > 0 && newLeadingPadding.isEmpty() && insert) {
                         // There's leading ComponentSprings, create an
                         // autopadding spring.
                         AutoPreferredGapSpring padding =

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/javax/swing/GroupLayout/8013566/bug8013566.java	Mon Apr 06 18:16:22 2015 +0400
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2015, 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 8013566
+   @summary Failure of GroupLayout in combination of addPreferredGap and addGroup's
+   last row
+   @author Semyon Sadetsky
+*/
+
+import javax.swing.*;
+
+public class bug8013566 {
+
+    public static void main(String[] args) throws Exception {
+        SwingUtilities.invokeAndWait(new Runnable() {
+            public void run() {
+                final JFrame frame = new JFrame();
+                try {
+                    frame.setUndecorated(true);
+                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+                    test(frame);
+
+
+                } finally {
+                    frame.dispose();
+                }
+            }
+        });
+
+        System.out.println("ok");
+    }
+
+    static void test(JFrame frame) {
+        JComponent c1 = new JButton("Label1");
+        JComponent c2 = new JButton("Label22");
+        JComponent c3 = new JButton("Label333");
+
+        JPanel panel = new JPanel();
+        GroupLayout layout = new GroupLayout(panel);
+        layout.setAutoCreateContainerGaps(true);
+        layout.setAutoCreateGaps(true);
+        panel.setLayout(layout);
+
+        layout.setHorizontalGroup(layout.createSequentialGroup().addGroup(
+                layout.createParallelGroup().addGroup(
+                        layout.createSequentialGroup().addComponent(c1)
+                                .addPreferredGap(
+                                        LayoutStyle.ComponentPlacement.RELATED,
+                                        50, 200))
+                        .addComponent(c2)).addComponent(c3));
+
+        layout.setVerticalGroup(layout.createSequentialGroup()
+                        .addComponent(c1).addComponent(c2).addComponent(c3)
+        );
+
+        frame.setContentPane(panel);
+        frame.pack();
+        frame.setVisible(true);
+
+        if (c3.getX() != c1.getX() + c1.getWidth() + 50) {
+            throw new RuntimeException(
+                    "Gap between 1st and 3rd component is wrong");
+        }
+
+    }
+}