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/navigator/CommonNavigator.java
/**
	 * <p>
	 * The Common Navigator Manager handles the setup of the Common Navigator
	 * Menu, manages updates to the ActionBars from
	 * {@link CommonActionProvider}&nbsp; extensions as the user's selection
	 * changes, and also updates the status bar based on the current selection.
	 * 
	 * @return The Common Navigator Manager class which handles menu population
	 *         and ActionBars
	 */
	protected CommonNavigatorManager createCommonManager() {
		return new CommonNavigatorManager(this);
	}
	/**
	 * <p>
	 * The ActionGroup is used to populate the ActionBars of Common Navigator
	 * View Part, and the returned implementation will have an opportunity to
	 * fill the ActionBars of the view as soon as it is created. ({@link ActionGroup#fillActionBars(org.eclipse.ui.IActionBars)}.
	 * </p>
	 * <p>
	 * The default implementation returns an action group which will add the
	 * following actions:
	 * <ul>
	 * <li>
	 * <p>
	 * Link with editor support. Allows the user to toggling linking the current
	 * selection with the active editors.
	 * </p>
	 * <li>
	 * <p>