Support timestamp clamping of "tIME" chunks in .png files. (Closes: #7)

use File::Basename qw/dirname/;

use POSIX qw/strftime/;

use List::Util qw/min/;

use Time::Local qw/timegm/;

sub crc($) {

	my ($data) = @_;

		pack('nCCCCC', 1900+$year, $mon+1, $mday, $hour, $min, $sec));

}

sub parse_time_chunk($) {

	my ($data) = @_;

	my ($year, $mon, $mday, $hour, $min, $sec) = unpack('nCCCCC', $data);

	return timegm($sec, $min, $hour, $mday, $mon, $year);

}

sub text_chunk($$) {

	my ($keyword, $data) = @_;

	return chunk('tEXt', pack('Z*a*', $keyword, $data));

			}

			if ($type eq "tIME") {

				print $tempfile time_chunk($canonical_time)

				  if defined($canonical_time);

				$modified = 1;

				next if not defined $canonical_time;

				my $timestamp = $canonical_time;

				$timestamp = min($timestamp, parse_time_chunk($data))

					if $File::StripNondeterminism::clamp_time;

				print $tempfile time_chunk($timestamp);

				next;

			} elsif (($type =~ /[tiz]EXt/)

				&& ($data =~ /^(date:[^\0]+|Creation Time)\0/)) {