Fix use last function result in LuaError::extract_message

CHANGELOG.md

@@ -39,6 +39,7 @@
 - Convert freed Object Variants (`<Freed Object>`) to `nil` when passing them to Lua
 - Fixed `LuaJIT core/library version mismatch` errors in LuaJIT builds
 - `LuaScriptResourceFormatLoader::_load` now respects the cache mode, fixing "Another resource is loaded from path 'res://...' (possible cyclic resource inclusion)." errors
+- Error messages from Lua code using the wrong stack index
 
 
 ## [0.5.0](https://github.com/gilzoide/lua-gdextension/releases/tag/0.5.0)

src/LuaError.cpp

@@ -75,7 +75,7 @@ String LuaError::extract_message(const sol::load_result& load_result) {
 }
 
 String LuaError::extract_message(const sol::protected_function_result& function_result) {
-	return luaL_tolstring(function_result.lua_state(), function_result.stack_index(), NULL);
+	return luaL_tolstring(function_result.lua_state(), function_result.stack_index() + function_result.return_count() - 1, NULL);
 }
 
 }