Bug 312540 [LinkedResources] Copy resource in Navigator and Project Explorer always shows dialog
N20100511-2000. When copying an IFile from one to another folder in the Navigator or Project Explorer, I always get the dialog no matter how I've set the preferences on the 'Linked Resources' page (even if I disable linked resources).
bundles/org.eclipse.ui.navigator.resources/src/org/eclipse/ui/navigator/resources/ResourceDropAdapterAssistant.java
*      java.lang.Object)
	 */
	public IStatus validatePluginTransferDrop(
			IStructuredSelection aDragSelection, Object aDropTarget) {
		if (!(aDropTarget instanceof IResource)) {
			return WorkbenchNavigatorPlugin
					.createStatus(
							IStatus.INFO,
							0,
							WorkbenchNavigatorMessages.DropAdapter_targetMustBeResource,
							null);
		}
		IResource resource = (IResource) aDropTarget;
		if (!resource.isAccessible()) {
			return WorkbenchNavigatorPlugin
					.createErrorStatus(
							0,
							WorkbenchNavigatorMessages.DropAdapter_canNotDropIntoClosedProject,
							null);
		}
		IContainer destination = getActualTarget(resource);
		if (destination.getType() == IResource.ROOT) {
			return WorkbenchNavigatorPlugin
					.createErrorStatus(
							0,
							WorkbenchNavigatorMessages.DropAdapter_resourcesCanNotBeSiblings,
							null);
		}
		IResource[] selectedResources = getSelectedResources(aDragSelection);
		String message = null;