From c340c2abec6ce8ce9f82d4e5a1fac7cc24950089 Mon Sep 17 00:00:00 2001
From: Ted John <ted@brambles.org>
Date: Fri, 23 Mar 2018 23:39:46 +0000
Subject: [PATCH] Fix segfault on exit

By ensuring duk_context is disposed last in ScriptEngine
---
 src/openrct2/scripting/ScriptEngine.cpp | 27 ++++++++++++++-----------
 src/openrct2/scripting/ScriptEngine.h   | 20 ++++++++++++++++--
 2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/src/openrct2/scripting/ScriptEngine.cpp b/src/openrct2/scripting/ScriptEngine.cpp
index 2e5a142f4e..82ba255bf3 100644
--- a/src/openrct2/scripting/ScriptEngine.cpp
+++ b/src/openrct2/scripting/ScriptEngine.cpp
@@ -31,6 +31,20 @@ using namespace OpenRCT2::Scripting;
 
 static std::string Stringify(duk_context * ctx, duk_idx_t idx);
 
+DukContext::DukContext()
+{
+    _context = duk_create_heap_default();
+    if (_context == nullptr)
+    {
+        throw std::runtime_error("Unable to initialise duktape context.");
+    }
+}
+
+DukContext::~DukContext()
+{
+    duk_destroy_heap(_context);
+}
+
 ScriptEngine::ScriptEngine(InteractiveConsole& console, IPlatformEnvironment& env) :
     _console(console),
     _env(env),
@@ -38,20 +52,9 @@ ScriptEngine::ScriptEngine(InteractiveConsole& console, IPlatformEnvironment& en
 {
 }
 
-ScriptEngine::~ScriptEngine()
-{
-    duk_destroy_heap(_context);
-}
-
 void ScriptEngine::Initialise()
 {
-    _context = duk_create_heap_default();
-    if (_context == nullptr)
-    {
-        throw std::runtime_error("Unable to initialise duktape context.");
-    }
-
-    auto ctx = _context;
+    auto ctx = (duk_context*)_context;
     ScConsole::Register(ctx);
     ScContext::Register(ctx);
     ScDisposable::Register(ctx);
diff --git a/src/openrct2/scripting/ScriptEngine.h b/src/openrct2/scripting/ScriptEngine.h
index a3f2cc0386..8d2f7b36a5 100644
--- a/src/openrct2/scripting/ScriptEngine.h
+++ b/src/openrct2/scripting/ScriptEngine.h
@@ -58,13 +58,30 @@ namespace OpenRCT2::Scripting
         std::shared_ptr<Plugin> GetCurrentPlugin() { return _plugin; }
     };
 
+    class DukContext
+    {
+    private:
+        duk_context * _context{};
+
+    public:
+        DukContext();
+        DukContext(DukContext&) = delete;
+        DukContext(DukContext&& src)
+            : _context(std::move(src._context))
+        {
+        }
+        ~DukContext();
+
+        operator duk_context*() { return _context; }
+    };
+
     class ScriptEngine
     {
     private:
         InteractiveConsole& _console;
         IPlatformEnvironment& _env;
+        DukContext _context;
         bool _initialised{};
-        duk_context * _context{};
         std::queue<std::tuple<std::promise<void>, std::string>> _evalQueue;
         std::vector<std::shared_ptr<Plugin>> _plugins;
         uint32 _lastHotReloadCheckTick{};
@@ -74,7 +91,6 @@ namespace OpenRCT2::Scripting
     public:
         ScriptEngine(InteractiveConsole& console, IPlatformEnvironment& env);
         ScriptEngine(ScriptEngine&) = delete;
-        ~ScriptEngine();
 
         HookEngine& GetHookEngine() { return _hookEngine; }