Venerable Monks,

I am using MP3::Tag for a very simple operation: parsing the id3v2 tag format into a %02d format for use with id3v1, like so:

#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;

use MP3::Tag;

my $filename = $ARGV[0];
die "Usage: $0 filename" unless $filename;

my $mp3 = MP3::Tag->new($filename);
$mp3->get_tags();
my $id3v1 = $mp3->{ID3v1} if exists $mp3->{ID3v1};
my $id3v2 = $mp3->{ID3v2} if exists $mp3->{ID3v2};

# Convert id3v2 track format to id3v1
my $track = $id3v2->track;
$track = sprintf( "%02d", (split(/\//, $track))[0] );
$id3v1->track($track);

$id3v1->write_tag();
[download]

Dumping $id3v1 right before the write_tag function shows the track field populated with "01". Dumping the tag after the write shows "1". I have torn apart both MP3::Tag and MP3::Tag::ID3v1 and I just cannot find anything that is truncating this data, althought MP3::Tag does refer to it:

I just can't find where that is actually implemented! Can anyone help me?