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
* @see org.eclipse.ui.navigator.CommonDropAdapterAssistant#validateDrop(java.lang.Object,
	 *      int, org.eclipse.swt.dnd.TransferData)
	 */
	public IStatus validateDrop(Object target, int aDropOperation,
			TransferData transferType) {
		if (!(target instanceof IResource)) {
			return WorkbenchNavigatorPlugin
					.createStatus(
							IStatus.INFO,
							0,
							WorkbenchNavigatorMessages.DropAdapter_targetMustBeResource,
							null);
		}
		IResource resource = (IResource) target;
		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);
		}
		String message = null;