post_install() {
  [ -x `which update-mime-database` ] && update-mime-database /usr/share/mime
  [ -x `which update-desktop-database` ] && update-desktop-database
  /bin/true
}

post_upgrade() {
  [ -x `which update-mime-database` ] && update-mime-database /usr/share/mime
  [ -x `which update-desktop-database` ] && update-desktop-database
  /bin/true
}