From 3f81494d4b14f3a8d6be0f9e9a489f0d26c88e37 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Sun, 24 May 2026 14:48:00 +0300
Subject: [PATCH] fix lua::bytearray_as_string

---
 src/logic/scripting/lua/lua_commons.hpp |  5 ++++
 src/logic/scripting/lua/lua_util.cpp    | 32 +++++++++++++++++++------
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/src/logic/scripting/lua/lua_commons.hpp b/src/logic/scripting/lua/lua_commons.hpp
index bb3163c86..8e77cbbc0 100644
--- a/src/logic/scripting/lua/lua_commons.hpp
+++ b/src/logic/scripting/lua/lua_commons.hpp
@@ -17,6 +17,11 @@
 #error LuaJIT required
 #endif
 
+#ifndef LUA_TCDATA
+// unsafe, use for filtering only
+#define LUA_TCDATA 10
+#endif
+
 namespace lua {
     class luaerror : public std::runtime_error {
     public:
diff --git a/src/logic/scripting/lua/lua_util.cpp b/src/logic/scripting/lua/lua_util.cpp
index ddd05cd19..090e47a5d 100644
--- a/src/logic/scripting/lua/lua_util.cpp
+++ b/src/logic/scripting/lua/lua_util.cpp
@@ -6,6 +6,7 @@
 
 #include "util/stringutil.hpp"
 #include "engine/Engine.hpp"
+#include "debug/Logger.hpp"
 
 using namespace lua;
 
@@ -13,6 +14,8 @@ static int next_environment = 1;
 
 std::unordered_map<std::type_index, std::string> lua::usertypeNames;
 
+static debug::Logger logger("lua-util");
+
 int lua::userdata_destructor(lua::State* L) {
     if (auto obj = touserdata<Userdata>(L, 1)) {
         obj->~Userdata();
@@ -371,10 +374,23 @@ void lua::remove_environment(State* L, int id) {
     store_env(L, id);
 }
 
+static inline std::string_view bytearray_as_string_indirect(lua::State* L, int idx) {
+    requireglobal(L, "Bytearray_as_string");
+    pushvalue(L, -2);
+    call(L, 1, 1);
+    auto view = tolstring(L, -1);
+    pop(L, 2);
+    return view;
+}
+
 std::string_view lua::bytearray_as_string(lua::State* L, int idx) {
     const auto& settings = scripting::engine->getSettings();
-    if (type(L, idx) == LUA_TSTRING) {
+
+    int luaType = type(L, idx);
+    if (luaType == LUA_TSTRING) {
         return tolstring(L, idx);
+    } else if (luaType == LUA_TTABLE) {
+        return bytearray_as_string_indirect(L, idx);
     }
     pushvalue(L, idx);
 
@@ -383,16 +399,18 @@ std::string_view lua::bytearray_as_string(lua::State* L, int idx) {
         pushvalue(L, -2);
         call(L, 1, 2);
         auto view = tolstring(L, -2);
+        if (view == "0") {
+            if (luaType == LUA_TCDATA) {
+                logger.error() << "FFI-based Bytearray_as_ptr returned null-pointer";
+            }
+            pop(L, 2);
+            return bytearray_as_string_indirect(L, idx);
+        }
         uint64_t size = touinteger(L, -1);
         auto ptr = (const char*)std::stoull(std::string(view), nullptr, 16);
         pop(L, 3);
         return std::string_view(ptr, size);
     } else {
-        requireglobal(L, "Bytearray_as_string");
-        pushvalue(L, -2);
-        call(L, 1, 1);
-        auto view = tolstring(L, -1);
-        pop(L, 2);
-        return view;
+        return bytearray_as_string_indirect(L, idx);
     }
 }