From 5df5cb9ff4917bff06d108c271f9a4c0158c0853 Mon Sep 17 00:00:00 2001
From: "lane.wei" <lane.wei@bambulab.com>
Date: Wed, 15 Feb 2023 12:03:55 +0800
Subject: [PATCH] FIX: smooth_nodes may crash due to broken parent-child chain

Change-Id: I770df691b41c6f18a0cb97e49e9e2251afe02e1a
(cherry picked from commit 2b5cdf0337fff277f7b949da568d6cdaa28a0d35)
---
 src/libslic3r/TreeSupport.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libslic3r/TreeSupport.cpp b/src/libslic3r/TreeSupport.cpp
index 81749e81c..84bec8acf 100644
--- a/src/libslic3r/TreeSupport.cpp
+++ b/src/libslic3r/TreeSupport.cpp
@@ -3000,7 +3000,11 @@ void TreeSupport::drop_nodes(std::vector<std::vector<Node*>>& contact_nodes)
                 std::vector<Node*>::iterator to_erase = std::find(contact_nodes[i_layer].begin(), contact_nodes[i_layer].end(), i_node);
                 if (to_erase != contact_nodes[i_layer].end())
                 {
-                    to_free_node_set.insert(*to_erase);
+                    // update the parent-child chain
+                    if(i_node->parent)
+                        i_node->parent->child = i_node->child;
+                    if(i_node->child)
+                        i_node->child->parent = i_node->parent;
                     contact_nodes[i_layer].erase(to_erase);
                     to_free_node_set.insert(i_node);