From 97a3d550c23d48ca532ebd13606170f1c109e755 Mon Sep 17 00:00:00 2001
From: John <github@slimeland.com>
Date: Mon, 30 May 2022 14:30:36 -0700
Subject: [PATCH] Fix stack overflow in debug builds in intrusive list dtor

When destroying large intrusive lists use iteration instead of
recursion.
---
 include/cppast/detail/intrusive_list.hpp | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/include/cppast/detail/intrusive_list.hpp b/include/cppast/detail/intrusive_list.hpp
index ac83239..a6ef5fb 100644
--- a/include/cppast/detail/intrusive_list.hpp
+++ b/include/cppast/detail/intrusive_list.hpp
@@ -20,13 +20,31 @@ namespace detail
     template <typename T>
     class intrusive_list_node
     {
-        std::unique_ptr<T> next_;
+    public:
+        intrusive_list_node() = default;
 
+        intrusive_list_node(intrusive_list_node&&) = default;
+        intrusive_list_node& operator=(intrusive_list_node&&) = default;
+
+        ~intrusive_list_node() noexcept
+        {
+            // Free iteratively to avoid stack overflow in debug builds.
+            auto next = next_.release();
+            while (next)
+            {
+                std::unique_ptr<T> cur(next);
+                next = cur->next_.release();
+            }
+        }
+
+    private:
         void do_on_insert(const T& parent) noexcept
         {
             static_cast<T&>(*this).on_insert(parent);
         }
 
+        std::unique_ptr<T> next_;
+
         template <typename U>
         friend struct intrusive_list_access;
     };