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/IOperationHistory.java
* <p>
	 * When an operation is open, operations that are added to the history will
	 * be considered part of the open operation instead. Their contexts will be
	 * assigned to the open operation and then they will be disposed. Operations
	 * that are executed while an operation is open will first be executed and
	 * then disposed.
	 * 
	 * <p>
	 * Open operations cannot be nested. If this method is called when another
	 * operation is open, that operation will be closed first.
	 * 
	 * @param operation -
	 *            the operation to be considered as the primary operation for
	 *            all subsequent operations.
	 * 
	 * <p>
	 * EXPERIMENTAL - this protocol is experimental and may change signficantly
	 * or be removed before the final release.
	 */
	void openOperation(IUndoableOperation operation);
	/**
	 * <p>
	 * The specified operation has changed in some way since it was added to the
	 * operation history. Notify listeners with an OPERATION_CHANGED event.
	 * 
	 * @param operation -
	 *            the operation that has changed.
	 * 
	 * <p>
	 * EXPERIMENTAL - this protocol is experimental and may change signficantly