[keycloak-dev] Locale lookup issue

Hello all, A little background information: In Keycloak 3.4.3.Final the following behaviour seems like a bug to me: * Use a theme with a country-specific locale, for example fr-FR and a default locale `english`  * Use Firefox on Ubuntu, drop all language preferences in its settings and just add `french` (no country specified) * request the login page * the theme will be rendered in english Acknowledging the RFC-4647 (1) Section 3.4; "Best Current Practice - Matching of Language Tags - Types of Matching - Lookup" I would expect basic matching to be applied so that the french language is chosen. The topic is discussed cotroversely in the original Pull Request (2). Therefor I have been asked to move a discussion from the Pull-Request to this mailing list. For more Info, see also the related issue (3) Thank you for your consideration. Kind regards,  Jochen Preusche (1) https://www.ietf.org/rfc/rfc4647.txt (2) https://github.com/keycloak/keycloak/pull/4958 (3) https://issues.jboss.org/browse/KEYCLOAK-6461