#!/bin/sh
set -e

# fontconfig creates non-reproducible files with UUIDs
# See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=864082
#
# Because the UUIDs should not be deleted, the proposed work-around is:
# * Use LD_PRELOAD to replace uuid_generate_random with a less random version

# Don't run if fontconfig is not installed
if [ ! -e /usr/bin/fc-cache ];
then
  exit 0
fi

# Don't run if fontconfig is sufficiently new
if dpkg --compare-versions $(dpkg-query --show --showformat '${Version}\n' fontconfig | head -1) ge 2.13.1-4.4~;
then
  exit 0
fi

# Don't run if there is no font in the initrd.img file
if ! lsinitramfs /initrd.img | grep "^var/cache/fontconfig" | grep ".cache-7$" > /dev/null;
then
  exit 0
fi

# Don't run if the LD_PRELOAD module is not compiled
if [ ! -e /usr/lib/unrandomize_uuid_generate_random.so ];
then
  echo "P: $(basename $0) Reproducible hook inactive: The UUID module was not found"
  exit 0
fi

LD_PRELOAD=/usr/lib/unrandomize_uuid_generate_random.so update-initramfs -k all -u
touch /initrd.img_has_already_been_regenerated

echo "P: $(basename $0) Reproducible hook has been applied"