From 1d94618c5e46a2f640a25d7d4982053bf2a74351 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Mon, 13 May 2013 12:52:57 +0200
Subject: [PATCH] Correctly detect external hole perimeters

---
 lib/Slic3r/Layer/Region.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index 7776d0848..19a30d87f 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -353,7 +353,9 @@ sub make_perimeters {
             push @loops, $traverse->($polynode->{children}, $depth+1, $is_contour);
 
             my $role = EXTR_ROLE_PERIMETER;
-            if ($depth == 0) {
+            if ($is_contour ? $depth == 0 : !@{ $polynode->{children} }) {
+                # external perimeters are root level in case of contours
+                # and items with no children in case of holes
                 $role = EXTR_ROLE_EXTERNAL_PERIMETER;
             } elsif ($depth == 1 && $is_contour) {
                 $role = EXTR_ROLE_CONTOUR_INTERNAL_PERIMETER;