Bug 88352 Operation supports leaks contexts via action handler
I20050315-1100 Susan, this is a different leak from the one that I reported. Test Case: 1. open text editor 2. close text editor ==> DefaultUndoManager is leaked due to undo/redo actions handlers still holding on to the context.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
for (int i = 0; i < listeners.size(); i++)
			try {
				((IOperationHistoryListener) listeners.get(i))
					.historyNotification(event);
			} catch (Exception e) {
				handleNotificationException(e);
			}
	}
	/*
	 * Notify listeners that an operation has been undone.
	 */
	protected void notifyUndone(IUndoableOperation operation) {
		OperationHistoryEvent event = new OperationHistoryEvent(
				OperationHistoryEvent.UNDONE, this, operation);
		preNotifyOperation(operation, event);
		for (int i = 0; i < listeners.size(); i++)
			try {
				((IOperationHistoryListener) listeners.get(i))
					.historyNotification(event);
			} catch (Exception e) {
				handleNotificationException(e);
			}
	}
	
	/*
	 * Notify listeners that an operation has been undone.
	 */
	protected void notifyChanged(IUndoableOperation operation) {
		OperationHistoryEvent event = new OperationHistoryEvent(
				OperationHistoryEvent.OPERATION_CHANGED, this, operation);