With 1.5-rc and 1.6-b1, I get the following exceptions when
running Java2Demo and switching tabs back and forth.
One can also reproduce it by running Java2Demo in automated mode:
java -jar Java2Demo.jar -runs=4 -sleep=1

This happens on all platforms. All systems it reproduced on were
multi-cpu systems (or systems with enabled HP).

Once the first exception is thrown, the app becomes unusable.

This particular stack trace happened on Solaris 9, Sparc,
2x1.2Ghz USIII.

#>../../../bin/java -jar Java2Demo.jar
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at java.awt.Dimension.<init>(Dimension.java:91)
        at java.awt.Component.getMaximumSize(Component.java:2343)
        at java.awt.Container.getMaximumSize(Container.java:1627)
        at javax.swing.JComponent.getMaximumSize(JComponent.java:1619)
        at javax.swing.BoxLayout.checkRequests(BoxLayout.java:435)
        at javax.swing.BoxLayout.layoutContainer(BoxLayout.java:375)
        at javax.swing.JToolBar$DefaultToolBarLayout.layoutContainer(JToolBar.java:788)
        at java.awt.Container.layout(Container.java:1401)
        at java.awt.Container.doLayout(Container.java:1390)
        at java.awt.Container.validateTree(Container.java:1473)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validate(Container.java:1448)
        at java2d.DemoGroup.setup(DemoGroup.java:258)
        at java2d.GlobalPanel.stateChanged(GlobalPanel.java:103)
        at javax.swing.JTabbedPane.fireStateChanged(JTabbedPane.java:290)
        at javax.swing.JTabbedPane$ModelListener.stateChanged(JTabbedPane.java:222)
        at javax.swing.DefaultSingleSelectionModel.fireStateChanged(DefaultSingleSelectionModel.java:116)
        at javax.swing.DefaultSingleSelectionModel.setSelectedIndex(DefaultSingleSelectionModel.java:50)
        at javax.swing.JTabbedPane.setSelectedIndexImpl(JTabbedPane.java:478)
        at javax.swing.JTabbedPane.setSelectedIndex(JTabbedPane.java:464)
        at javax.swing.plaf.basic.BasicTabbedPaneUI$Handler.mousePressed(BasicTabbedPaneUI.java:3209)
        at java.awt.Component.processMouseEvent(Component.java:5485)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3093)
        at java.awt.Component.processEvent(Component.java:5253)
        at java.awt.Container.processEvent(Container.java:1966)
        at java.awt.Component.dispatchEventImpl(Component.java:3955)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3889)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
        at java.awt.Container.dispatchEventImpl(Container.java:2010)
        at java.awt.Window.dispatchEventImpl(Window.java:1766)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:234)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at javax.swing.SizeRequirements.calculateTiledPositions(SizeRequirements.java:294)
        at javax.swing.BoxLayout.layoutContainer(BoxLayout.java:378)
        at javax.swing.JToolBar$DefaultToolBarLayout.layoutContainer(JToolBar.java:788)
        at java.awt.Container.layout(Container.java:1401)
        at java.awt.Container.doLayout(Container.java:1390)
        at java.awt.Container.validateTree(Container.java:1473)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validate(Container.java:1448)
        at javax.swing.RepaintManager.validateInvalidComponents(RepaintManager.java:379)
        at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:113)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:234)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at javax.swing.SizeRequirements.calculateTiledPositions(SizeRequirements.java:294)
        at javax.swing.BoxLayout.layoutContainer(BoxLayout.java:378)
        at javax.swing.JToolBar$DefaultToolBarLayout.layoutContainer(JToolBar.java:788)
        at java.awt.Container.layout(Container.java:1401)
        at java.awt.Container.doLayout(Container.java:1390)
        at java.awt.Container.validateTree(Container.java:1473)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validateTree(Container.java:1480)
        at java.awt.Container.validate(Container.java:1448)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.ensureCurrentLayout(BasicTabbedPaneUI.java:1226)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.getTabBounds(BasicTabbedPaneUI.java:1246)
        at javax.swing.plaf.basic.BasicTabbedPaneUI$Handler.focusLost(BasicTabbedPaneUI.java:3258)
        at java.awt.Component.processFocusEvent(Component.java:5380)
        at java.awt.Component.processEvent(Component.java:5244)
        at java.awt.Container.processEvent(Container.java:1966)
        at java.awt.Component.dispatchEventImpl(Component.java:3955)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1810)
        at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:836)
        at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:526)
        at java.awt.Component.dispatchEventImpl(Component.java:3841)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.SentEvent.dispatch(SentEvent.java:50)
        at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:161)
        at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:188)
        at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:591)
        at java.awt.Component.dispatchEventImpl(Component.java:3841)
        at java.awt.Container.dispatchEventImpl(Container.java:2024)
        at java.awt.Window.dispatchEventImpl(Window.java:1766)
        at java.awt.Component.dispatchEvent(Component.java:3803)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at java.awt.SequencedEvent.dispatch(SequencedEvent.java:93)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:234)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)

###@###.### 2004-09-07