[bug-libextractor] Handling MP3 files: duplicate types

[Debarshi 'Rishi' Ray]

While using 'extract' to read the meta information from MP3 files,
which contain both the ID3v1 and ID3v2 tags, keywords belonging to
duplicate types are returned.

Here is an example:
address@hidden tmp]$ extract tune.mp3
format - 96 kbps, 44100 hz, 5m03 stereo
resource-type - MPEG V1
mimetype - audio/mpeg
description - Eagles                        : New Kid In Town
     (Hotel California              )
comment -
genre - Rock
date - 1976
album - Hotel California
artist - Eagles
title - New Kid In Town
title - New Kid In Town
artist - Eagles
album - Hotel California
genre - rock
media type - DIG
address@hidden tmp]$ extract -p title tune.mp3
title - New Kid In Town
title - New Kid In Town
address@hidden tmp]$ extract -d title tune.mp3
format - 96 kbps, 44100 hz, 5m03 stereo
resource-type - MPEG V1
mimetype - audio/mpeg
description - Eagles                        : New Kid In Town
     (Hotel California              )
comment -
genre - Rock
date - 1976
album - Hotel California
artist - Eagles
title - New Kid In Town
title - New Kid In Town
artist - Eagles
album - Hotel California
genre - rock
media type - DIG
address@hidden tmp]$

Is not 'extract' supposed to suppress the duplicate types? I am using
version 0.5.13.

Happy hacking,
Debarshi
--
It matters not whether you win or lose; what matters is whether I win or lose.
                                           - Darrin Weinberg