From ca0b218a56ab502a2c51f5e9d7d67ee6a12bbe35 Mon Sep 17 00:00:00 2001
From: Lukas Matena <lukasmatena@seznam.cz>
Date: Fri, 10 Mar 2023 08:38:21 +0100
Subject: [PATCH] Fix of a crash in bridging over sparse #9996

---
 src/libslic3r/PrintObject.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index b9552a2ef..bee233e59 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -1658,7 +1658,9 @@ void PrintObject::bridge_over_infill()
             }
 
             // generate sparse infill polylines from lower layers to get anchorable polylines
-            Polylines lower_layer_polylines = po->get_layer(lidx)->lower_layer->generate_sparse_infill_polylines_for_anchoring();
+            Polylines lower_layer_polylines = po->get_layer(lidx)->lower_layer
+                ? po->get_layer(lidx)->lower_layer->generate_sparse_infill_polylines_for_anchoring();
+                : Polylines();
 
             for (std::pair<const LayerSlice *, SurfacesPtr> candidates : bridging_surface_candidates) {
                 if (candidates.second.empty()) {