From 92dec2db2a67c4d7144ae008a61213c084de5ec2 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Tue, 4 Oct 2011 22:36:05 +0200
Subject: [PATCH] Fixed detection of horizontal shells

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

diff --git a/lib/Slic3r/STL.pm b/lib/Slic3r/STL.pm
index 44a229357..5407f6054 100644
--- a/lib/Slic3r/STL.pm
+++ b/lib/Slic3r/STL.pm
@@ -117,7 +117,9 @@ sub _facet {
     Slic3r::debugf "layers: min = %s, max = %s\n", $min_layer, $max_layer;
     
     # is the facet horizontal?
-    if ($min_layer == $max_layer) {
+    # (note that we can have $min_z == $max_z && $min_layer != $max_layer
+    # if $min_z % $layer_height != 0)
+    if ($min_z == $max_z) {
         Slic3r::debugf "Facet is horizontal\n";
         my $layer = $print->layer($min_layer);
         my $surface = $layer->add_surface(@vertices);