From db55bd706ee22cf08e6b6288521595af2e9864e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Hejl?= <hejl.lukas@gmail.com>
Date: Tue, 27 Apr 2021 00:36:22 +0200
Subject: [PATCH] Fixed case in MMU segmentation when the infinity-edge in the
 Voronoi diagram has vertex0(), and vertex1() equals nullptr.

---
 src/libslic3r/MultiMaterialSegmentation.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libslic3r/MultiMaterialSegmentation.cpp b/src/libslic3r/MultiMaterialSegmentation.cpp
index 865e0aaa4d..c3f2fed13d 100644
--- a/src/libslic3r/MultiMaterialSegmentation.cpp
+++ b/src/libslic3r/MultiMaterialSegmentation.cpp
@@ -795,7 +795,7 @@ static MMU_Graph build_graph(size_t layer_idx, const std::vector<std::vector<Col
         if (edge_it->cell()->source_index() > edge_it->twin()->cell()->source_index() || edge_it->color())
             continue;
 
-        if (edge_it->is_infinite()) {
+        if (edge_it->is_infinite() && (edge_it->vertex0() != nullptr || edge_it->vertex1() != nullptr)) {
             // Infinite edge is leading through a point on the counter, but there are no Voronoi vertices.
             // So we could fix this case by computing the intersection between the contour line and infinity edge.
             std::vector<Voronoi::Internal::point_type> samples;