X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FText%2FTradition%2FCollation%2FRelationshipStore.pm;h=de125331a6ccd61e0b70bb443dcb38c90daa9e7e;hb=a30ca502de98d06d416f352736ae855185eabb86;hp=dc2fe1b2245a96e9ec93e0aeae04033d80e483a8;hpb=d6936deaa42cead642f7e4f3dc1a4e9c01fb8027;p=scpubgit%2Fstemmatology.git

diff --git a/lib/Text/Tradition/Collation/RelationshipStore.pm b/lib/Text/Tradition/Collation/RelationshipStore.pm
index dc2fe1b..de12533 100644
--- a/lib/Text/Tradition/Collation/RelationshipStore.pm
+++ b/lib/Text/Tradition/Collation/RelationshipStore.pm
@@ -537,6 +537,7 @@ sub _as_graphml {
     my $edge_ctr = 0;
     foreach my $e ( sort { $a->[0] cmp $b->[0] } $self->graph->edges ) {
     	# Add an edge and fill in its relationship info.
+    	next unless( exists $node_hash->{$e->[0]} && exists $node_hash->{$e->[1]} );
 		my $edge_el = $rgraph->addNewChild( $graphml_ns, 'edge' );
 		$edge_el->setAttribute( 'source', $node_hash->{$e->[0]} );
 		$edge_el->setAttribute( 'target', $node_hash->{$e->[1]} );