Documents in default packages cannot be opened

When a document is located in a default package (e.g. directly under src), the editor crashes. This is because JavaModelUtils.getPackageContainingFile and its caller always expects some nested package. The method uses JavaCore.create(IFolder), which normally returns an IPackageFragment. When the folder corresponds to a default package, however, an IPackageFragmentRoot is returned, instead, and this causes the attempted cast to fail.

Relevant portion of the stack trace: Caused by: java.lang.NullPointerException at no.tobask.sb4e.JavaProjectGlossary.queryControllerClasses(JavaProjectGlossary.java:58) at com.oracle.javafx.scenebuilder.app.info.InfoPanelController.getSuggestedControllerClasses(InfoPanelController.java:421) at com.oracle.javafx.scenebuilder.app.info.InfoPanelController.performInitialization(InfoPanelController.java:187) at com.oracle.javafx.scenebuilder.app.info.InfoPanelController.controllerDidLoadFxml(InfoPanelController.java:174) at com.oracle.javafx.scenebuilder.kit.editor.panel.util.AbstractFxmlPanelController.makePanel(AbstractFxmlPanelController.java:89) ... 89 more