--- a/src/java.desktop/share/classes/javax/swing/JRootPane.java	Wed Oct 11 15:53:25 2017 +0100
+++ b/src/java.desktop/share/classes/javax/swing/JRootPane.java	Thu Oct 12 10:40:45 2017 +0530
@@ -922,7 +922,7 @@
                 rd = new Dimension(Integer.MAX_VALUE,
                         Integer.MAX_VALUE - i.top - i.bottom - mbd.height - 1);
             }
-            return new Dimension(Math.min(rd.width, mbd.width) + i.left + i.right,
+            return new Dimension(Math.max(rd.width, mbd.width) + i.left + i.right,
                                          rd.height + mbd.height + i.top + i.bottom);
         }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/javax/swing/JRootPane/MaximumSizeTest.java	Thu Oct 12 10:40:45 2017 +0530
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2009, 2017, 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 6714836
+ * @summary Tests if the maximum size of a JRootPane is appropriate.
+ * @run main MaximumSizeTest
+ */
+import javax.swing.SwingUtilities;
+import javax.swing.JRootPane;
+import javax.swing.JLabel;
+import java.awt.Dimension;
+import java.lang.reflect.InvocationTargetException;
+
+public class MaximumSizeTest {
+    public static void main(String args[]) {
+        try {
+            SwingUtilities.invokeAndWait(() -> {
+                JRootPane r = new JRootPane();
+                r.getContentPane().add(new JLabel("foo"));
+                System.out.println("Min Size: " + r.getMinimumSize());
+                System.out.println("Preferred Size: " + r.getPreferredSize());
+
+                Dimension d = r.getMaximumSize();
+                if (d.width == 0 || d.height == 0) {
+                    throw new RuntimeException("Maximum size is wrongly reported: " + d);
+                }
+
+                System.out.println("Max size: " + d);
+            });
+        } catch (InterruptedException | InvocationTargetException e) {
+            System.out.println(e.getCause());
+            throw new RuntimeException(e.getMessage());
+        }
+    }
+}