fix bug in transposition validation

[scpubgit/stemmatology.git] / lib / Text / Tradition / Collation.pm

diff --git a/lib/Text/Tradition/Collation.pm b/lib/Text/Tradition/Collation.pm
index 6558587..4c410c1 100644 (file)
--- a/lib/Text/Tradition/Collation.pm
+++ b/lib/Text/Tradition/Collation.pm
@@ -37,6 +37,7 @@ has 'relations' => (
 has 'tradition' => (
     is => 'ro',
     isa => 'Text::Tradition',
+    writer => '_set_tradition',
     weak_ref => 1,
     );
 
@@ -1492,8 +1493,8 @@ sub calculate_ranks {
             $r->rank( $node_ranks->{$rel_containers{$r->id}} );
         } else {
                # Die. Find the last rank we calculated.
-               my @all_defined = sort { $node_ranks->{$rel_containers{$a->id}}
-                                <=> $node_ranks->{$rel_containers{$b->id}} }
+               my @all_defined = sort { ( $node_ranks->{$rel_containers{$a->id}}||-1 )
+                                <=> ( $node_ranks->{$rel_containers{$b->id}}||-1 ) }
                        $self->readings;
                my $last = pop @all_defined;
             throw( "Ranks not calculated after $last - do you have a cycle in the graph?" );