The use of C stdlib localization functions (toupper, mbrtowc, etc), makes me suspect if there will be some regex behavior differences between systems or locales.
Redis sets the locale at startup to avoid issues so should be ok but we will document that for instance è will not match È when nocase is used.
Redis sets the locale at startup to avoid issues so should be ok but we will document that for instance è will not match È when nocase is used.