Revert "Revert "reproducible: Support arbitrary package filters when generating deb822 output.""

# helper functions

packages_list_to_deb822() {

	ALL_PKGS=$(cat $TMPFILE | cut -d ":" -f1 | sed "s#([^()]*)##g ; s#\[[^][]*\]##g ; s#,##g ; s# #\n#g"  |sort -u | tr '\n' '|')

	grep-dctrl -F Package -e '^('"$ALL_PKGS"')$' $PACKAGES > $TMPFILE

	script=$(cat <<'EOF'

		use Dpkg::Control;

		my $fd;

		open($fd, '<', $ARGV[0]) or die $!;

		my %packages = map { chomp; $_ => 1 } <STDIN>;

		while (1) {

			my $deb822 = Dpkg::Control->new();

			last unless $deb822->parse($fd);

			print "$deb822\n" if $packages{$deb822->{'Package'}};

		}

		close($fd);

EOF

	)

	perl -e "$script" $PACKAGES < $TMPFILE > $TMPFILE2

	mv $TMPFILE2 $TMPFILE

}

tails_build_manifest_to_deb822() {