From df6f7e2315dac278fd9f30533b1a38d83ff060ab Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 14 Jan 2019 15:23:33 +0000
Subject: [PATCH] wip

---
 parse-input-graph | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/parse-input-graph b/parse-input-graph
index 37e7a54..cec240a 100755
--- a/parse-input-graph
+++ b/parse-input-graph
@@ -159,7 +159,6 @@ sub dual () {
   # anticlockwise end of the i'th listed edge of Region Name.
 
   foreach my $ra (sort keys %region) {
-    next if $ra eq 'L' or $ra eq 'NZ';
     my $adjsa = $region{$ra}{Adj};
     foreach my $adjia (0..$#$adjsa) {
       my $adja = $adjsa->[$adjia];
@@ -167,7 +166,8 @@ sub dual () {
       # $va is the vertex at the anticlockwise end
       # of edge no.$adjia of region $ra
       my $rb = $adja->{Name};
-      next if $rb eq 'L' or $rb eq 'NZ';
+      next if ($rb eq 'L' or $rb eq 'NZ') and
+	      ($ra eq 'L' or $ra eq 'NZ');
       # $rb is the region on the other side of that edge
       my $adjsb = $region{$rb}{Adj};
       foreach my $adjib (0..$#$adjsb) {
-- 
2.30.2