I try to automate my tests by running them with DISPLAY set to an
Xvfb server I maintain. If I run the "java2demo" basic acceptance test
like this:

/java/jdk/bin/jdkx2 -b /some/jdk java2demo

then it intermittently fails (20% of the time?) when DISPLAY is
an Xvfb server.

To reproduce, log onto "suttles.sfbay" and set DISPLAY=lasker:7

Then

repeat 5 DISPLAY=lasker:7 /java/jdk/bin/jdkx2 -b ~/ws/mustang/build/solaris-sparc java2demo

eventually gives:

cd /u/martin/ws/mustang/build/solaris-sparc/demo/jfc/Java2D
/u/martin/ws/mustang/build/solaris-sparc/bin/java -jar Java2Demo.jar -runs=1 -delay=5 -ccthread

Java2D Demo RunWindow : 1 Runs, 5 second delay between tabs
java version: 1.6.0-internal
SunOS 5.9

#0 Wed Dec 01 20:31:33 PST 2004, 4303.242K used
Exception in thread "RunWindow" java.lang.NullPointerException
at java.awt.Dimension.<init>(Dimension.java:91)
at java.awt.Component.getMaximumSize(Component.java:2346)
at java.awt.Container.getMaximumSize(Container.java:1627)
at javax.swing.JComponent.getMaximumSize(JComponent.java:1659)
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 java2d.RunWindow.run(RunWindow.java:220)
at java.lang.Thread.run(Thread.java:595)
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$DefaultToolBarLayout.layoutContainer(JToolBar.java:788)
at java.awt.Container.layout(Container.java:1401)
at java.awt.Container.doLayout(Container.java:1390)
at java.awt.Container.validateTree(Container.java:1473)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validateTree(Container.java:1480)
at java.awt.Container.validate(Container.java:1448)
at javax.swing.RepaintManager.validateInvalidComponents(RepaintManager.java:398)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:113)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:589)
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)