From 99c1facec6b6812538bcdda719c3a979f649c296 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Wed, 7 Dec 2011 20:18:12 +0100
Subject: [PATCH] Bugfix: division by zero when nothing in a single layer could
 be parsed. #100

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

diff --git a/lib/Slic3r/TriangleMesh.pm b/lib/Slic3r/TriangleMesh.pm
index 6e5a537bf..5032fe25a 100644
--- a/lib/Slic3r/TriangleMesh.pm
+++ b/lib/Slic3r/TriangleMesh.pm
@@ -200,7 +200,9 @@ sub make_loops {
         my $total_discarded_length = 0;
         $total_discarded_length += $_->length for map polyline_lines($_), @discarded_polylines;
         $total_discarded_length += $_->length for @discarded_lines;
-        my $discarded_ratio = $total_discarded_length / $total_detected_length;
+        my $discarded_ratio = $total_detected_length
+            ? ($total_discarded_length / $total_detected_length)
+            : 0;
         
         Slic3r::debugf "  length ratio of discarded lines is %f\n", $discarded_ratio;