Bug 266699 [CommonNavigator] Remove CommonDropAdapter.setCurrentOperation
This has been replaced by overrideOperation() which does the same thing. Note that setCurrentOperation() was added in M5 so it's never really been API yet.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonDropAdapter.java
* 
	 * @see org.eclipse.swt.dnd.DropTargetAdapter#dragLeave(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dragLeave(DropTargetEvent event) {
		super.dragLeave(event);
		if (LocalSelectionTransfer.getTransfer().isSupportedType(
				event.currentDataType)) {
			event.data = NavigatorPluginDropAction
					.createTransferData(contentService);
		}
	}
	public boolean performDrop(Object data) {
		DropTargetEvent event = getCurrentEvent();
		if (Policy.DEBUG_DND) {
			System.out.println("CommonDropAdapter.drop (begin): " + event); 
		}
		Object target = getCurrentTarget() != null ? 
				getCurrentTarget() : getViewer().getInput();
		 
		
		 
		
		validateDrop(target, getCurrentOperation(), event.currentDataType);
		if (PluginTransfer.getInstance().isSupportedType(event.currentDataType)) {
			super.drop(event);
			return true;
		}
		
		if (Policy.DEBUG_DND) {
			System.out.println("CommonDropAdapter.drop target: " + target + " op: " + getCurrentOperation());