Bug 169591 [Common Navigator] Show In fails for editor inputs
The show(ShowInContext) method for CommonNavigator only considers the selection of the context. When Show In Project Explorer is performed from an editor, the selection is empty and the input is provided. Unfortunately, this is problematic, as the show-in target needs to adapt the input to an IFile so this will probably need to have some sort of extension so that the Project Explorer can plug-in the proper support.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/CommonNavigatorActionGroup.java
private LinkEditorAction toggleLinkingAction;
	private CollapseAllAction collapseAllAction;
	private FilterActionGroup filterGroup;
	private final CommonViewer commonViewer;
	private CommonNavigator commonNavigator;
	/**
	 * Create a action group for Collapse All, Link with editor, and Select
	 * Filters.
	 * 
	 * @param aNavigator
	 *            The IViewPart for this action group
	 * @param aViewer
	 *            The Viewer for this action group
	 */
	public CommonNavigatorActionGroup(CommonNavigator aNavigator,
			CommonViewer aViewer) {
		super();
		commonNavigator = aNavigator;
		commonViewer = aViewer;
		makeActions();
	}
	/**
	 * Returns the image descriptor with the given relative path.
	 */