Bug 114491 [refactoring] CCE in NullRefactoringHistory
3.2 M3 test pass I deleted some projects in (Java and Resource) working sets, but not quite sure what action triggered the exception. !ENTRY org.eclipse.core.resources 4 2 2005-11-01 11:29:35.216 !MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.core.resources". !STACK 0 java.lang.ClassCastException: org.eclipse.ltk.internal.core.refactoring.history.RefactoringHistoryService$NullRefactoringHistory at org.eclipse.ltk.internal.core.refactoring.history.RefactoringHistoryService$WorkspaceChangeListener.removeDescriptors(RefactoringHistoryService.java:410) at org.eclipse.ltk.internal.core.refactoring.history.RefactoringHistoryService$WorkspaceChangeListener.resourceChanged(RefactoringHistoryService.java:454) at org.eclipse.core.internal.events.NotificationManager$2.run(NotificationManager.java:276) at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1044) at org.eclipse.core.runtime.Platform.run(Platform.java:783) at org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:270) at org.eclipse.core.internal.events.NotificationManager.handleEvent(NotificationManager.java:254) at org.eclipse.core.internal.resources.Workspace.broadcastEvent(Workspace.java:201) at org.eclipse.core.internal.resources.Resource.unprotectedDelete(Resource.java:1573) at org.eclipse.core.internal.resources.Resource.delete(Resource.java:670) at org.eclipse.core.internal.resources.Project.delete(Project.java:332) at org.eclipse.ui.actions.DeleteResourceAction.delete(DeleteResourceAction.java:419) at org.eclipse.ui.actions.DeleteResourceAction.delete(DeleteResourceAction.java:395) at org.eclipse.ui.actions.DeleteResourceAction.access$0(DeleteResourceAction.java:385) at org.eclipse.ui.actions.DeleteResourceAction$3.run(DeleteResourceAction.java:502) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1705) at org.eclipse.ui.actions.DeleteResourceAction$2.run(DeleteResourceAction.java:500) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:76)
org.eclipse.ltk.core.refactoring/src/org/eclipse/ltk/internal/core/refactoring/history/RefactoringHistoryService.java
/**
		 * {@inheritDoc}
		 */
		public void resourceChanged(final IResourceChangeEvent event) {
			final int type= event.getType();
			if ((type & IResourceChangeEvent.PRE_DELETE) != 0) {
				resetStacks(event);
				removeDescriptors(event);
			} else if ((type & IResourceChangeEvent.PRE_CLOSE) != 0)
				resetStacks(event);
		}
	}
	
	private static RefactoringHistoryService fInstance= null;
	
	private static final int MAX_UNDO_STACK= 25;
	
	public static final String NAME_REFACTORING_HISTORY= "refactorings.history"; 
	
	public static final String NAME_REFACTORINGS_FOLDER= ".refactorings"; 
	
	private static final NullRefactoringHistory NO_HISTORY= new NullRefactoringHistory();
	
	private static final String UNKNOWN_REFACTORING_ID= "org.eclipse.ltk.core.refactoring.unknown.refactoring"; 
	/**
	 * Returns the singleton instance of the refactoring history.
	 * 
	 * @return the singleton instance
	 */
	public static RefactoringHistoryService getInstance() {