Bug 94438 [Undo] - javadoc - clarify operation remaining in history for undo/redo with INFO/WARNING
The javadoc for the IOperationHistory#undo(...) redo(...) methods is very explicit about the operation remaining in the history on CANCEL and ERROR status, and that it is moved between undo/redo histories when ok. Some minor clarifications: The lack of an explicit statement about INFO and WARNING makes one wonder what happens to the operation. It remains in the history in this case also... Technically, on OK status the operation is not guaranteed to move between the stacks. If it cannot redo after undoing, or cannot undo after redoing, it won't be transferred to the other stack, but in effect will be removed from the history.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/IOperationHistory.java
* Close the current operation. If the operation has successfully completed,
	 * send listeners a <code>DONE</code>, <code>UNDONE</code>, or
	 * <code>REDONE</code> notification, depending on the mode. Otherwise send
	 * an <code>OPERATION_NOT_OK</code> notification. Add the operation to the
	 * history if specified and send an <code>OPERATION_ADDED</code>
	 * notification.
	 * </p>
	 * <p>
	 * Any operations that are executed and added after this operation is closed
	 * will no longer be considered part of this operation.
	 * </p>
	 * <p>
	 * This method has no effect if the caller has not previously called
	 * {@link #openOperation}.
	 * </p>
	 * 
	 * @param operationOK
	 *            <code>true</code> if the operation successfully completed.
	 *            Listeners should be notified with <code>DONE</code>,
	 *            <code>UNDONE</code>, or <code>REDONE</code>.
	 *            <code>false</code> if the operation did not successfully
	 *            complete. Listeners should be notified with
	 *            <code>OPERATION_NOT_OK</code>.
	 * @param addToHistory
	 *            <code>true</code> if the operation should be added to the
	 *            history, <code>false</code> if it should not. If the
	 *            <code>operationOK</code> parameter is <code>false</code>,
	 *            the operation will never be added to the history.
	 * @param mode
	 *            the mode the operation was opened in. Can be one of