post_install() {
  # Ensure that the ld.so.conf file contains the xulrunner libs.
  cp -f /etc/ld.so.conf /tmp/ld.so.conf
  grep -v xulrunner /tmp/ld.so.conf > /etc/ld.so.conf
  echo /usr/lib/xulrunner-1.9.1.1 >> /etc/ld.so.conf
  /sbin/ldconfig
}

post_upgrade() {
  post_install $*
}