This test fails in mach5 time to time:
java.lang.NullPointerException
at java.desktop/javax.swing.plaf.nimbus.NimbusStyle.validate(NimbusStyle.java:304)
at java.desktop/javax.swing.plaf.nimbus.NimbusStyle.getValues(NimbusStyle.java:820)
at java.desktop/javax.swing.plaf.nimbus.NimbusStyle.getInsets(NimbusStyle.java:493)
at java.desktop/javax.swing.plaf.synth.SynthStyle.installDefaults(SynthStyle.java:915)
at java.desktop/javax.swing.plaf.synth.SynthLookAndFeel.updateStyle(SynthLookAndFeel.java:270)
at java.desktop/javax.swing.plaf.synth.SynthComboBoxUI.updateStyle(SynthComboBoxUI.java:127)
at java.desktop/javax.swing.plaf.synth.SynthComboBoxUI.installDefaults(SynthComboBoxUI.java:120)
at java.desktop/javax.swing.plaf.basic.BasicComboBoxUI.installUI(BasicComboBoxUI.java:287)
at java.desktop/javax.swing.plaf.synth.SynthComboBoxUI.installUI(SynthComboBoxUI.java:115)
at java.desktop/javax.swing.JComponent.setUI(JComponent.java:685)
at java.desktop/javax.swing.JComboBox.setUI(JComboBox.java:265)
at java.desktop/javax.swing.JComboBox.updateUI(JComboBox.java:277)
at java.desktop/javax.swing.JComboBox.init(JComboBox.java:236)
at java.desktop/javax.swing.JComboBox.<init>(JComboBox.java:230)
at bug7031551.testRawSignatures(bug7031551.java:53)
at bug7031551.main(bug7031551.java:44)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainActionHelper$SameVMRunnable.run(MainActionHelper.java:229)
at java.base/java.lang.Thread.run(Thread.java:841)