Bug 189490 [CommonNavigator] Go To->Resource won't enable
I0524 1. Open the Project Explorer in the Resource perspective 2. Create a vanilla project P 3. Create a folder F 4. Create a file resource R Open the Navigate->Go To file. "Resource..." will remain disabled.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
if (selection != null && !selection.isEmpty() && selection instanceof IStructuredSelection)
			return (IStructuredSelection)selection;
		Object input = context.getInput();
		if (input instanceof IEditorInput) {
			LinkHelperService lhs = getLinkHelperService();
			return lhs.getSelectionFor((IEditorInput) input);
		}
		if (input != null) {
			return new StructuredSelection(input);
		}
		return StructuredSelection.EMPTY;
	}
	/**
	 * @since 3.4
	 */
	protected synchronized LinkHelperService getLinkHelperService() {
		if (linkService == null)
			linkService = new LinkHelperService((NavigatorContentService)getCommonViewer().getNavigatorContentService());
		return linkService;
	}
	
	/**
	 * @since 3.4
	 */
	protected IMemento getMemento() {
		return memento;
	}
 
}