Bug 123316 [Undo] - API BEHAVIOR - should always place a successfully undone/redone op on the redo/undo history
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
boolean addToRedoStack = operation.canRedo();
			synchronized (undoRedoHistoryLock) {
				undoList.remove(operation);
				if (addToRedoStack && checkRedoLimit(operation)) {
					redoList.add(operation);
				}
			}
			if (!addToRedoStack) {
				
				
				
				operation.dispose();
			}
			
			
			notifyUndone(operation);
		} else {
			notifyNotOK(operation, status);
		}
		return status;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#execute(org.eclipse.core.commands.operations.IUndoableOperation,
	 *      org.eclipse.core.runtime.IProgressMonitor,
	 *      org.eclipse.core.runtime.IAdaptable)