. "$BST_LIB"
require tar tar/present

# The shipped /usr/bin/tar must be GNU tar (update-alternatives winner over the
# busybox applet); busybox tar lacks the long-option surface dpkg-deb --build needs.
check_out tar/gnu-version "GNU tar" tar --version

tmp=${TMPDIR:-/tmp}/bst-tar.$$
mkdir -p "$tmp/src/sub"
line="the quick brown fox jumps over the lazy dog 0123456789"
i=0
while [ $i -lt 32 ]; do printf "%s\n" "$line"; i=$((i+1)); done > "$tmp/src/a.txt"
printf "nested payload\n" > "$tmp/src/sub/b.txt"

# Archive to STDOUT, not a named file: the shell opens the output and tar writes
# stdout. This is how dpkg-deb --build drives tar. (Named-file mode is below.)
check     tar/create      sh -c "cd '$tmp' && tar -cf - src > '$tmp/arc.tar'"
# the long-option / --format surface busybox tar rejects but dpkg-deb --build needs.
check     tar/dpkg-opts   sh -c "cd '$tmp' && tar --format=gnu --owner=0 --group=0 -cf - src > '$tmp/dpkg.tar'"
# list enumerates members from the stream; the nested path proves recursion.
check_out tar/list        "src/sub/b.txt"  sh -c "tar -tf - < '$tmp/arc.tar'"

# extract from the stream. The owner/perms/mtime restore is skipped
# (--no-same-owner --no-same-permissions -m); file content still round-trips,
# which is what dpkg-deb -x relies on.
# BRINTOS-WORKAROUND: linux#5 revisit — these three flags were added because
# chown/fchmod/utimes were ENOSYS; the syscalls are wired now, but chown is a
# documented accept-and-succeed no-op for uid/gid on virtio-fs, so asserting a
# restored owner needs judgement rather than just dropping the flags.
mkdir -p "$tmp/out"
check     tar/extract     sh -c "cd '$tmp/out' && tar --no-same-owner --no-same-permissions -m -xf - < '$tmp/arc.tar'"
check     tar/identical   cmp -s "$tmp/src/a.txt" "$tmp/out/src/a.txt"

# gzip round-trip via the pipe form dpkg builds data.tar.gz with (busybox gzip).
check     tar/gzip-create sh -c "cd '$tmp' && tar -cf - src | gzip -c > '$tmp/arc.tgz'"
check_out tar/gzip-list   "src/a.txt"  sh -c "gunzip -c '$tmp/arc.tgz' | tar -tf -"

# Named-file archive mode (tar -cf FILE) — the common create form, and the only
# one that reaches creat(2). Round-trip it rather than just checking tar's exit
# status: a create that silently produced an unreadable archive would still be 0.
check     tar/named-create  sh -c "cd '$tmp' && tar -cf '$tmp/named.tar' src"
check_out tar/named-list    "src/sub/b.txt"  tar -tf "$tmp/named.tar"
mkdir -p "$tmp/nout"
check     tar/named-extract sh -c "cd '$tmp/nout' && tar --no-same-owner --no-same-permissions -m -xf '$tmp/named.tar'"
check     tar/named-ident   cmp -s "$tmp/src/a.txt" "$tmp/nout/src/a.txt"

rm -rf "$tmp"