The Portlet API 2.0 TCK has a check for no supported/specified locales in the portlet descriptor.
This means that PortletConfig.getSupportedLocales() should in that case return an empty Enumeration.
As Jetspeed maps and stores the supported locales and the (possibly) provided predefined portlet "PortletInfo" elements from a resource bundle in its Language OM, we need to keep track if a Language is created for such a supported-locale definition by or for the Portlet descriptor.
Most specifically, the "default" (English) Language is always created and on the fly by Jetspeed (and should not be allowed to be removed!)
using either the inline PortletInfo definition in the portlet descriptor or, if a ResourceBundle is provided, taking overrides from its English ResourceBundle.
If however there is no <supported-locale>en</supported-locale> defined, this "default" Language may not be used to represent the formally supported locales.
This will be implemented by adding a supportedLocale boolean on Language and only set to true for those locales as specified by <supported-locale/> definitions in the portlet descriptor.