post_install() {
  [ -x `which update-desktop-database 2>/dev/null` ] &&  update-desktop-database -q
}

pre_upgrade() {
  pre_remove
}

post_upgrade() {
  post_install
}

post_remove() {
  [ -x `which update-desktop-database 2>/dev/null` ] &&  update-desktop-database -q
}