Bug 105697 [Undo] - OperationHistoryEvent - cannot distinguish between canceled event or failed event
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
operation.dispose();
				}
			} else {
				notifyNotOK(operation);
				
				
				operation.dispose();
			}
		} 
		
		return status;
	}
	/*
	 * Filter the specified list to include only the specified undo context.
	 */
	private IUndoableOperation[] filter(List list, IUndoContext context) {
		/*
		 * This method is used whenever there is a need to filter the undo or
		 * redo history on a particular context. Currently there are no caches
		 * kept to optimize repeated requests for the same filter. If benchmarks
		 * show this to be a common pattern that causes performances problems,
		 * we could implement a filtered cache here that is nullified whenever
		 * the global history changes.
		 */
		List filtered = new ArrayList();
		Iterator iterator = list.iterator();
		synchronized (undoRedoHistoryLock) {
			while (iterator.hasNext()) {
				IUndoableOperation operation = (IUndoableOperation) iterator