mmdebstrap/tests/check-for-bit-by-bit-identical-format-output

#!/bin/sh
set -eu
export LC_ALL=C.UTF-8
export SOURCE_DATE_EPOCH={{ SOURCE_DATE_EPOCH }}

trap "rm -f /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }} /tmp/debian-chroot-root.{{ FORMAT }}" EXIT INT TERM

[ "$(id -u)" -eq 0 ]

if ! id "${SUDO_USER:-user}" 2>/dev/null; then
	if [ ! -e /mmdebstrap-testenv ]; then
		echo "this test modifies the system and should only be run inside a container" >&2
		exit 1
	fi
	useradd --home-dir "/home/${SUDO_USER:-user}" --create-home "${SUDO_USER:-user}"
fi
prefix="runuser -u ${SUDO_USER:-user} --"

{{ CMD }} --mode=root --variant={{ VARIANT }} {{ DIST }} /tmp/debian-chroot-root.{{ FORMAT }} {{ MIRROR }}
if [ "{{ FORMAT }}" = tar ]; then
	printf 'ustar ' | cmp --bytes=6 --ignore-initial=257:0 /tmp/debian-chroot-root.tar -
elif [ "{{ FORMAT }}" = squashfs ]; then
	printf 'hsqs' | cmp --bytes=4 /tmp/debian-chroot-root.squashfs -
elif [ "{{ FORMAT }}" = ext2 ]; then
	printf '\123\357' | cmp --bytes=2 --ignore-initial=1080:0 /tmp/debian-chroot-root.ext2 -
else
	echo "unknown format: {{ FORMAT }}" >&2
	exit 1
fi

$prefix {{ CMD }} --mode={{ MODE }} --variant={{ VARIANT }} {{ DIST }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }} {{ MIRROR }}
cmp /tmp/debian-chroot-root.{{ FORMAT }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }} \
	|| diffoscope /tmp/debian-chroot-root.{{ FORMAT }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }}

# we cannot test chrootless mode here, because mmdebstrap relies on the
# usrmerge package to set up merged-/usr and that doesn't work in chrootless
# mode