If an artist has multiple performer credits we end up with duplicate values

Description

If an artist has multiple performer credits we end up with duplicate values in track artist.

For example in this track:

http://musicbrainz.org/recording/974de7cf-27b8-4b6e-87c5-cd8d8c31cc6d

(publicshaw exmaple)
Peter Gabriel has three different musical credits If an artist has multiple performer credits we end up with dupliciate values in

Performing Artist or Performing Soloist
Performing Artist Sort or Performing Soloist Sort
Artist
Artist Sort

Environment

None

Status

Assignee

Unassigned

Reporter

Paul Taylor

Labels

None

Forum Username

paul

os

None

Components

Fix versions

Affects versions

4.0

Priority

Major
Configure