--- a/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicTabbedPaneUI.java	Thu Mar 07 12:51:02 2019 +0530
+++ b/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicTabbedPaneUI.java	Fri Mar 08 14:07:10 2019 +0530
@@ -3322,11 +3322,11 @@
     private class TabbedPaneScrollLayout extends TabbedPaneLayout {
 
         protected int preferredTabAreaHeight(int tabPlacement, int width) {
-            return calculateMaxTabHeight(tabPlacement);
+            return calculateTabAreaHeight(tabPlacement, 1, calculateMaxTabHeight(tabPlacement));
         }
 
         protected int preferredTabAreaWidth(int tabPlacement, int height) {
-            return calculateMaxTabWidth(tabPlacement);
+            return calculateTabAreaWidth(tabPlacement, 1, calculateMaxTabWidth(tabPlacement));
         }
 
         @SuppressWarnings("deprecation")

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/javax/swing/JTabbedPane/TabProb.java	Fri Mar 08 14:07:10 2019 +0530
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2019, 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 8215396
+   @key headful
+   @summary Verifies JTabbedPane preferred size calculation is wrong
+   for SCROLL_TAB_LAYOUT.
+   @run main TabProb
+ */
+
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.Color;
+import java.awt.BorderLayout;
+import java.awt.Dimension;
+import java.awt.LayoutManager;
+import java.awt.Insets;
+import java.awt.Robot;
+import javax.swing.BorderFactory;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+import javax.swing.JTabbedPane;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+
+public class TabProb extends JFrame {
+    static TabProb tb1;
+    static TabProb tb2;
+    class FixLayout implements LayoutManager {
+        @Override
+        public void layoutContainer(Container C) {
+            Insets in = C.getInsets();
+            int w = 200 - in.left - in.right;
+            int h = 100 - in.top - in.bottom;
+            C.getComponents()[0].setBounds(in.top, in.left, w, h);
+        }
+        @Override
+        public Dimension minimumLayoutSize(Container C) {
+            return new Dimension(200, 100);
+        }
+        @Override
+        public Dimension preferredLayoutSize(Container C) {
+            return new Dimension(200, 100);
+        }
+        @Override
+        public void removeLayoutComponent(Component c) {
+        }
+        @Override
+        public void addLayoutComponent(String s, Component c) {
+        }
+    }
+
+    public TabProb(int layoutPolicy) {
+        JTabbedPane tabpanel = new JTabbedPane();
+        tabpanel.setTabPlacement(JTabbedPane.TOP);
+        tabpanel.setTabLayoutPolicy(layoutPolicy);
+        JPanel panel = new JPanel(new FixLayout());
+        JLabel label = new JLabel("Label");
+        label.setBorder(BorderFactory.createLineBorder(Color.green, 3));
+        panel.add(label);
+        tabpanel.add("TEST", panel);
+        add(tabpanel, BorderLayout.CENTER);
+        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
+    }
+
+    public static void main(String[] args) throws Exception {
+        for (UIManager.LookAndFeelInfo laf : UIManager.getInstalledLookAndFeels()) {
+            System.out.println("Test for LookAndFeel " + laf.getClassName());
+            UIManager.setLookAndFeel(laf.getClassName());
+            test();
+            System.out.println("Test passed for LookAndFeel " + laf.getClassName());
+        }
+    }
+
+    public static void test() throws Exception {
+        Robot robot = new Robot();
+        SwingUtilities.invokeAndWait(new Runnable() {
+            @Override
+            public void run() {
+                tb1 = new TabProb(JTabbedPane.SCROLL_TAB_LAYOUT);
+                tb1.pack();
+                tb1.setVisible(true);
+
+                tb2 = new TabProb(JTabbedPane.WRAP_TAB_LAYOUT);
+                tb2.pack();
+                tb2.setVisible(true);
+            }
+        });
+        double tb1height = tb1.getPreferredSize().getHeight();
+        double tb2height = tb2.getPreferredSize().getHeight();
+        System.out.println(tb1height);
+        System.out.println(tb2height);
+
+        robot.waitForIdle();
+        robot.delay(2000);
+
+        SwingUtilities.invokeAndWait(() -> tb1.dispose());
+        SwingUtilities.invokeAndWait(() -> tb2.dispose());
+
+        if (tb1height != tb2height) {
+            throw new RuntimeException("JTabbedPane preferred size calculation is wrong for SCROLL_TAB_LAYOUT");
+        }
+    }
+}