From 2def6a9787556fda137b464d39122fcc7f98d612 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Fri, 30 Dec 2011 18:58:27 +0100
Subject: [PATCH] Bugfix: medial axis code threw fatal errors sometimes

---
 lib/Slic3r/ExPolygon.pm | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Slic3r/ExPolygon.pm b/lib/Slic3r/ExPolygon.pm
index 6dd78cf8..50c9deba 100644
--- a/lib/Slic3r/ExPolygon.pm
+++ b/lib/Slic3r/ExPolygon.pm
@@ -201,6 +201,7 @@ sub medial_axis {
             $pointmap{$_->[A]} >= 2 && $pointmap{$_->[B]} >= 2
         } @skeleton_lines;
     }
+    return undef if !@skeleton_lines;
     
     # now build a single polyline
     my $polyline = [];