From 5c8ff73fb13e1a610dfcd7b1e4f697c6cbb26b50 Mon Sep 17 00:00:00 2001
From: Vojtech Bubnik <bubnikv@gmail.com>
Date: Fri, 25 Mar 2022 14:40:51 +0100
Subject: [PATCH] Follow-up to bdb8c3729f393a80810924de4cec02a1502e50c7 Fixing
 ExtrusionEntityCollection append move operator (fixing double destruction of
 ExtrusionEntityCollections)

---
 src/libslic3r/ExtrusionEntityCollection.hpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/libslic3r/ExtrusionEntityCollection.hpp b/src/libslic3r/ExtrusionEntityCollection.hpp
index 864528352e..130bdc83c1 100644
--- a/src/libslic3r/ExtrusionEntityCollection.hpp
+++ b/src/libslic3r/ExtrusionEntityCollection.hpp
@@ -68,6 +68,9 @@ public:
             entities.insert(entities.end(),
                 std::make_move_iterator(src.begin()),
                 std::make_move_iterator(src.end()));
+            // Removing pointers to polymorphic extrusions from the donor object
+            // so that they will not be deleted twice.
+            src.clear();
         }
     }
     void append(const ExtrusionPaths &paths) {