Scrollable tab button of JTabbedPane is not disabled when reaches the last tab in the JTabbedPane .

The above behaviour is noticed only when the size of the JtabbedPane is less than the size of a single tab. It works fine when JTabbedPane is resize to more than the size of a single tab.

Find attached test case with the bug report.

To Reproduce the bug :

1) Compile and run the attached Java File.
2) Click on the scroll button until it reaches the last tab. Check to see if the scroll button is still enabled/disabled. It should be disabled when reaching the last tab.

This Results in the following exception.

Exception occurred during event dispatching:
java.lang.ArrayIndexOutOfBoundsException
        at javax.swing.plaf.basic.BasicTabbedPaneUI$ScrollTabsForwardAction.actionPerformed(BasicTabbedPaneUI.java:1823)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1580)
        at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1634)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:379)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:251)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:247)
        at java.awt.Component.processMouseEvent(Component.java:4137)
        at java.awt.Component.processEvent(Component.java:3963)
        at java.awt.Container.processEvent(Container.java:1247)
        at java.awt.Component.dispatchEventImpl(Component.java:2892)
        at java.awt.Container.dispatchEventImpl(Container.java:1309)
        at java.awt.Component.dispatchEvent(Component.java:2764)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3029)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2783)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2742)
        at java.awt.Container.dispatchEventImpl(Container.java:1283)
        at java.awt.Window.dispatchEventImpl(Window.java:1228)
        at java.awt.Component.dispatchEvent(Component.java:2764)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:423)
        at java.awt.EventDispatchThread.pumpOneEvent(EventDispatchThread.java:136)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:122)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:118)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:98)