From 73763a8417751b6f45e71cebad6bf4a8a8827993 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Thu, 22 Dec 2016 13:18:22 +0100
Subject: [PATCH] Bugfix: rare crash when loading 3D preview. #3636

---
 xs/src/slic3r/GUI/3DScene.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xs/src/slic3r/GUI/3DScene.cpp b/xs/src/slic3r/GUI/3DScene.cpp
index e398a1c37..519f96aa9 100644
--- a/xs/src/slic3r/GUI/3DScene.cpp
+++ b/xs/src/slic3r/GUI/3DScene.cpp
@@ -8,6 +8,8 @@ _3DScene::_extrusionentity_to_verts_do(const Lines &lines, const std::vector<dou
         const std::vector<double> &heights, bool closed, double top_z, const Point &copy,
         GLVertexArray* qverts, GLVertexArray* tverts)
 {
+    if (lines.empty()) return;
+    
     /* It looks like it's faster without reserving capacity...
     // each segment has 4 quads, thus 16 vertices; + 2 caps
     qverts->reserve_more(3 * 4 * (4 * lines.size() + 2));