From 964c44cdcd6be5f39aed1aeda9c305803eb3b25f Mon Sep 17 00:00:00 2001
From: Hodlinator <172445034+hodlinator@users.noreply.github.com>
Date: Wed, 25 Jun 2025 14:17:14 +0200
Subject: [PATCH] test(miniscript): Prove avoidance of stack overflow
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Can be tested through emptying the function body of ~Node() or replacing Clone() implementation with naive version:
```C++
Node<Key> Clone() const
{
    std::vector<Node> new_subs;
    new_subs.reserve(subs.size());
    for (const Node& child : subs) {
        new_subs.push_back(child.Clone());
    }
    return Node{internal::NoDupCheck{}, m_script_ctx, fragment, std::move(new_subs), keys, data, k};
}
```

Co-authored-by: Lőrinc <pap.lorinc@gmail.com>
---
 src/test/miniscript_tests.cpp | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/test/miniscript_tests.cpp b/src/test/miniscript_tests.cpp
index 0cd5b62f7de..757f89b63bc 100644
--- a/src/test/miniscript_tests.cpp
+++ b/src/test/miniscript_tests.cpp
@@ -727,4 +727,25 @@ BOOST_AUTO_TEST_CASE(fixed_tests)
     g_testdata.reset();
 }
 
+// Confirm that ~Node(), Node::Clone() and operator=(Node&&) are stack-safe.
+BOOST_AUTO_TEST_CASE(node_deep_destruct)
+{
+    using miniscript::internal::NoDupCheck;
+    using miniscript::Fragment;
+    using NodeU32 = miniscript::Node<uint32_t>;
+
+    constexpr auto ctx{miniscript::MiniscriptContext::P2WSH};
+
+    NodeU32 root{NoDupCheck{}, ctx, Fragment::JUST_1};
+    for (uint32_t i{0}; i < 200'000; ++i) {
+        root = NodeU32{NoDupCheck{}, ctx, Fragment::WRAP_S, Vector(std::move(root))};
+    }
+    BOOST_CHECK_EQUAL(root.ScriptSize(), 200'001);
+
+    auto clone{root.Clone()};
+    BOOST_CHECK_EQUAL(clone.ScriptSize(), root.ScriptSize());
+
+    clone = std::move(root);
+}
+
 BOOST_AUTO_TEST_SUITE_END()