Bug 89031 [Undo/Redo] IWorkbench#getOperationSupport() marked experimental
IWorkbench#getOperationSupport() marked experimental
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
* If we are in the middle of executing an open batching operation, and this is not that
		 * operation, then we need only add the context of the new operation to the batch.  
		 * The operation itself is disposed since we will never undo or redo it.  We consider
		 * it to be triggered by the batching operation and assume that its undo will be triggered
		 * by the batching operation undo.  
		 */
		if (openComposite != null && openComposite != operation) {
			openComposite.add(operation);
			return;
		}
		
		if (checkUndoLimit(operation)) {
			undoList.add(operation);
			notifyAdd(operation);
		
			
			IUndoContext[] contexts = operation.getContexts();
			for (int i = 0; i < contexts.length; i++) {
				flushRedo(contexts[i]);
			}
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#addOperationApprover(org.eclipse.core.commands.operations.IOperationApprover)
	 */
	public void addOperationApprover(IOperationApprover approver) {
		approvers.add(approver);
	}