nattable: java.lang.IllegalArgumentException

[mxz297]

With hpcviewer built with commit ab056cc, I encountered an "Internal Error" on my Macbook. This error can be reproduced by:

1. Open the database (on ufront, /home/xm13/warpx-debug-pc.d.zip)
2. Click "Flat view" tab
3. Click the "Flatten nodes one level" bottom four times
4. Click "GINS:Sum(E)" metric column

A pop-up window appears:

[laksono]

The problem is consistently reproducible and happens when sorting the column, and somehow the sort criteria is not consistent for flattened tree of this database. With other databases it works just fine.
The complete call stack of the exception:

java.lang.IllegalArgumentException: Comparison method violates its general contract!
	at java.base/java.util.TimSort.mergeHi(TimSort.java:903)
	at java.base/java.util.TimSort.mergeAt(TimSort.java:520)
	at java.base/java.util.TimSort.mergeCollapse(TimSort.java:448)
	at java.base/java.util.TimSort.sort(TimSort.java:245)
	at java.base/java.util.Arrays.sort(Arrays.java:1515)
	at org.eclipse.collections.impl.list.mutable.FastList.sort(FastList.java:283)
	at edu.rice.cs.hpctree.ScopeTreeData.sort(ScopeTreeData.java:129)
	at edu.rice.cs.hpctree.ScopeTreeRowModel.sort(ScopeTreeRowModel.java:125)
	at org.eclipse.nebula.widgets.nattable.sort.command.SortCommandHandler.lambda$0(SortCommandHandler.java:50)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:74)
	at org.eclipse.nebula.widgets.nattable.sort.command.SortCommandHandler.doCommand(SortCommandHandler.java:51)
	at org.eclipse.nebula.widgets.nattable.sort.command.SortCommandHandler.doCommand(SortCommandHandler.java:1)
	at org.eclipse.nebula.widgets.nattable.command.AbstractLayerCommandHandler.doCommand(AbstractLayerCommandHandler.java:22)
	at org.eclipse.nebula.widgets.nattable.layer.AbstractLayer.doCommand(AbstractLayer.java:186)
	at org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform.doCommand(AbstractLayerTransform.java:104)
	at org.eclipse.nebula.widgets.nattable.layer.CompositeLayer.doCommandOnChildLayers(CompositeLayer.java:159)
	at org.eclipse.nebula.widgets.nattable.layer.CompositeLayer.doCommand(CompositeLayer.java:151)
	at org.eclipse.nebula.widgets.nattable.NatTable.doCommand(NatTable.java:827)
	at org.eclipse.nebula.widgets.nattable.sort.action.SortColumnAction.run(SortColumnAction.java:32)
	at org.eclipse.nebula.widgets.nattable.ui.mode.MouseModeEventHandler.executeClickAction(MouseModeEventHandler.java:194)
	at org.eclipse.nebula.widgets.nattable.ui.mode.MouseModeEventHandler.mouseUp(MouseModeEventHandler.java:94)
	at org.eclipse.nebula.widgets.nattable.ui.mode.ModeSupport.mouseUp(ModeSupport.java:117)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:224)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4441)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1512)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1535)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1520)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1324)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4227)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3837)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1157)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1046)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:168)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	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:566)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1461)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1434)