Bug 41701 Cannot open AntEditor due to NPE in ExtendedTextEditor
in 20030819: java.lang.NullPointerException at java.lang.Throwable.<init>(Throwable.java) at java.lang.Throwable.<init>(Throwable.java) at java.lang.NullPointerException.<init>(NullPointerException.java:63) at org.eclipse.ui.texteditor.ExtendedTextEditor.initializeChangeRulerColumn(ExtendedTextEditor.java:509) at org.eclipse.ui.texteditor.ExtendedTextEditor.createChangeRulerColumn(ExtendedTextEditor.java:595) at org.eclipse.ui.texteditor.ExtendedTextEditor.createCompositeRuler(ExtendedTextEditor.java:619) at org.eclipse.ui.texteditor.ExtendedTextEditor.createVerticalRuler(ExtendedTextEditor.java:603) at org.eclipse.ui.texteditor.AbstractTextEditor.createPartControl(AbstractTextEditor.java:2047) at org.eclipse.ui.texteditor.StatusTextEditor.createPartControl(StatusTextEditor.java:53) at org.eclipse.ui.texteditor.ExtendedTextEditor.createPartControl(ExtendedTextEditor.java:259) at org.eclipse.ui.internal.PartPane$4.run(PartPane.java:141) at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java) at org.eclipse.core.runtime.Platform.run(Platform.java) at org.eclipse.ui.internal.PartPane.createChildControl(PartPane.java:137) at org.eclipse.ui.internal.PartPane.createControl(PartPane.java:186) at org.eclipse.ui.internal.EditorWorkbook.createPage(EditorWorkbook.java:404) at org.eclipse.ui.internal.EditorWorkbook.add(EditorWorkbook.java:123) at org.eclipse.ui.internal.EditorArea.addEditor(EditorArea.java:55) at org.eclipse.ui.internal.EditorPresentation.openEditor(EditorPresentation.java:351) at org.eclipse.ui.internal.EditorManager$2.run(EditorManager.java:585) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java) at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:574) at org.eclipse.ui.internal.EditorManager.openInternalEditor(EditorManager.java:668) at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:459) at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:431) at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2069) at org.eclipse.ui.internal.WorkbenchPage.access$6(WorkbenchPage.java:2019) at org.eclipse.ui.internal.WorkbenchPage$9.run(WorkbenchPage.java:2006) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2001) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:1894) at org.eclipse.ui.actions.OpenWithMenu.openEditor(OpenWithMenu.java:237) at org.eclipse.ui.actions.OpenWithMenu.access$0(OpenWithMenu.java:231) at org.eclipse.ui.actions.OpenWithMenu$2.handleEvent(OpenWithMenu.java:155) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1676) at org.eclipse.ui.internal.Workbench.run(Workbench.java:1659) at org.eclipse.core.internal.boot.InternalBootLoader.run(InternalBootLoader.java:858) at org.eclipse.core.boot.BootLoader.run(BootLoader.java:461) at java.lang.reflect.AccessibleObject.invokeL(AccessibleObject.java:207) at java.lang.reflect.Method.invoke(Method.java:271) at org.eclipse.core.launcher.Main.basicRun(Main.java:291) at org.eclipse.core.launcher.Main.run(Main.java:747) at org.eclipse.core.launcher.Main.main(Main.java:583)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
if (fSelectionHistory != null) {
			fSelectionHistory.dispose();
			fSelectionHistory= null;
		}
		
		if (fEditorSelectionChangedListener != null)  {
			fEditorSelectionChangedListener.uninstall(getSelectionProvider());
			fEditorSelectionChangedListener= null;
		}
				
		super.dispose();
	}
	
	protected void createActions() {
		super.createActions();
		
		ResourceAction resAction= new AddTaskAction(JavaEditorMessages.getResourceBundle(), "AddTask.", this); 
		resAction.setHelpContextId(IAbstractTextEditorHelpContextIds.ADD_TASK_ACTION);
		resAction.setActionDefinitionId(ITextEditorActionDefinitionIds.ADD_TASK);
		setAction(ITextEditorActionConstants.ADD_TASK, resAction);
		ActionGroup oeg, ovg, jsg, sg;
		fActionGroups= new CompositeActionGroup(new ActionGroup[] {
			oeg= new OpenEditorActionGroup(this),
			sg= new ShowActionGroup(this),
			ovg= new OpenViewActionGroup(this),
			jsg= new JavaSearchActionGroup(this)
		});
		fContextMenuGroup= new CompositeActionGroup(new ActionGroup[] {oeg, ovg, sg, jsg});