Allow any-of simple search over subjects

Fixes #15

InSubject mints a new prefix in join and logic, but SubQuery (as inherited by
OrSubQuery) only uses the join from the first sub-op. Hence the perfix used in
logic for any other ORed InSubject sub-ops would not match the prefix used in
the join.

Fixed by always setting a prefix in the call to join() and logic() - empty
string so we don't make the SQL any more difficult to read than it already is.

perl_lib/EPrints/Search/Condition/OrSubQuery.pm

@@ -27,15 +27,6 @@ use EPrints::Search::Condition::SubQuery;
 
 use strict;
 
-sub logic
-{
-	my( $self, %opts ) = @_;
-
-	my @logic = map { $_->logic( %opts ) } @{$self->{sub_ops}};
-
-	return @logic ? "(".join(" OR ", @logic).")" : ();
-}
-
 1;
 
 =head1 COPYRIGHT

perl_lib/EPrints/Search/Condition/SubQuery.pm

@@ -46,14 +46,22 @@ sub joins
 {
 	my( $self, %opts ) = @_;
 
+	# Stop sub_ops from using their own prefixes (InSubject)
+	$opts{prefix} = "" if !defined $opts{prefix};
+
 	return $self->{sub_ops}->[0]->joins( %opts );
 }
 
 sub logic
 {
 	my( $self, %opts ) = @_;
 
-	return "(" . join(" OR ", map { $_->logic( %opts ) } @{$self->{sub_ops}} ) . ")";
+	# Stop sub_ops from using their own prefixes (InSubject)
+	$opts{prefix} = "" if !defined $opts{prefix};
+
+	my @logic = map { $_->logic( %opts ) } @{$self->{sub_ops}};
+
+	return @logic ? "(".join(" OR ", @logic).")" : ();
 }
 
 sub alias