Additiopnal code to deal with document pos when merging EPrints.

Symplectic_RepoProcess_MergeManager.pm

# Based on EPrints::DataObj::Document::clone
# NB Code duplication with Symplectic::RepoProcess::MergeManager
# 
# Cloning documents can result in:
# - two documents with the same 'pos' field - and therefore sharing the same folder
# - 'spaces' in the document structure (e.g. pos=1 and pos=3, but no pos=2)
# this isn't what is needed. The code below manages these scenarios.
# EPrints' default behaviour is to remove the 'pos' during a clone *only* when the doc is being cloned to the same parent.
sub clone_document
{
        my ($self, %args ) = @_;
        my $eprint = $args{'eprint'};
        my $doc = $args{'doc'};
        my $reset_pos = $args{'reset_pos'};

        my $data = EPrints::Utils::clone( $doc->{data} );

        # cloning within the same eprint, in which case get a new position!
        #if( defined $doc->parent && $eprint->id eq $doc->parent->id )
        if( ( defined $doc->parent && $eprint->id eq $doc->parent->id ) || $reset_pos )
        {
                $data->{pos} = undef;
        }

        $data->{eprintid} = $eprint->get_id;
        $data->{_parent} = $eprint;

        # First create a new doc object
        my $new_doc = $doc->{dataset}->create_object( $doc->{session}, $data );
        return undef if !defined $new_doc;

        my $ok = 1;

        # Copy files
        foreach my $file (@{$doc->get_value( "files" )})
        {
                $file->clone( $new_doc ) or $ok = 0, last;
        }

        if( !$ok )
        {
                $new_doc->remove();
                return undef;
        }

        return $new_doc;
}