nav_title_close(): check for NULL
nav_title_close(): check for NULL

mwgoldsmith/bluray,mwgoldsmith/bluray,ShiftMediaProject/libbluray,Azzuro/libbluray,ace20022/libbluray,ShiftMediaProject/libbluray,ShiftMediaProject/libbluray,Azzuro/libbluray,tourettes/libbluray,ace20022/libbluray,Azzuro/libbluray,mwgoldsmith/bluray,tourettes/libbluray,ace20022/libbluray,ShiftMediaProject/libbluray,tourettes/libbluray,Azzuro/libbluray,tourettes/libbluray,mwgoldsmith/bluray,ace20022/libbluray