From 513abd332c3256774314bba239b956ef03b3f16e Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Wed, 29 Jul 2026 20:02:30 +0300
Subject: [PATCH] add platform::new_engine_instance subProcess parameter

---
 src/logic/scripting/lua/libs/libapp.cpp |  3 +-
 src/util/platform.cpp                   | 73 ++++++++++++++++++++++++-
 src/util/platform.hpp                   |  4 +-
 3 files changed, 77 insertions(+), 3 deletions(-)

diff --git a/src/logic/scripting/lua/libs/libapp.cpp b/src/logic/scripting/lua/libs/libapp.cpp
index 6442fcbad..12758c724 100644
--- a/src/logic/scripting/lua/libs/libapp.cpp
+++ b/src/logic/scripting/lua/libs/libapp.cpp
@@ -365,7 +365,8 @@ static int l_start_debug_instance(lua::State* L) {
 
     platform::new_engine_instance(
         std::move(args),
-        outputPath.empty() ? "" : io::resolve(std::string(outputPath))
+        outputPath.empty() ? "" : io::resolve(std::string(outputPath)),
+        true // debug instance may be detached
     );
     return lua::pushinteger(L, port);
 }
diff --git a/src/util/platform.cpp b/src/util/platform.cpp
index f113641e5..76ed8a973 100644
--- a/src/util/platform.cpp
+++ b/src/util/platform.cpp
@@ -18,7 +18,11 @@
 #pragma comment(lib, "winmm.lib")
 #else
 #include <sys/poll.h>
+#include <sys/prctl.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
 #endif
 
 namespace platform::internal {
@@ -216,7 +220,9 @@ std::filesystem::path platform::get_executable_path() {
 }
 
 void platform::new_engine_instance(
-    const std::vector<std::string>& args, std::filesystem::path outputFile
+    const std::vector<std::string>& args,
+    std::filesystem::path outputFile,
+    bool subProcess
 ) {
     auto executable = get_executable_path();
 
@@ -285,6 +291,37 @@ void platform::new_engine_instance(
         &si,
         &pi
     );
+    if (subProcess) {
+        HANDLE job = CreateJobObjectW(nullptr, nullptr);
+
+        JOBOBJECT_EXTENDED_LIMIT_INFORMATION info{};
+        info.BasicLimitInformation.LimitFlags =
+            JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
+
+        try {
+            if (!SetInformationJobObject(
+                job,
+                JobObjectExtendedLimitInformation,
+                &info,
+                sizeof(info))) {
+                throw std::runtime_error(
+                    "SetInformationJobObject failed with code: " +
+                    std::to_string(GetLastError())
+                );
+            }
+            if (!AssignProcessToJobObject(job, pi.hProcess)) {
+                throw std::runtime_error(
+                    "SetInformationJobObject failed with code: " +
+                    std::to_string(GetLastError())
+                );
+            }
+        } catch (const std::exception& err) {
+            CloseHandle(job);
+            CloseHandle(pi.hProcess);
+            CloseHandle(pi.hThread);
+            return;
+        }
+    }
     if (success) {
         CloseHandle(pi.hProcess);
         CloseHandle(pi.hThread);
@@ -295,6 +332,40 @@ void platform::new_engine_instance(
         );
     }
 #else
+
+    if (subProcess) {
+        pid_t pid = fork();
+
+        int fd = open(
+            outputFile.string().c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644
+        );
+
+        if (pid == 0) {
+            prctl(PR_SET_PDEATHSIG, SIGTERM);
+
+            if (getppid() == 1) {
+                _exit(1);
+            }
+
+            dup2(fd, STDOUT_FILENO);
+            dup2(fd, STDERR_FILENO);
+            close(fd);
+
+            std::vector<const char*> argv(args.size() + 2);
+            argv[0] = const_cast<char*>(executable.c_str());
+            for (int i = 0; i < args.size(); i++) {
+                argv[i + 1] = args[i].c_str();
+            }
+            argv[args.size() + 1] = nullptr;
+
+            execvp(executable.c_str(), const_cast<char**>(argv.data()));
+
+            _exit(127);
+        } else {
+            close(fd);
+        }
+    }
+
     std::stringstream ss;
     ss << executable;
     for (int i = 0; i < args.size(); i++) {
diff --git a/src/util/platform.hpp b/src/util/platform.hpp
index 54c56a0c5..2ff535248 100644
--- a/src/util/platform.hpp
+++ b/src/util/platform.hpp
@@ -19,7 +19,9 @@ namespace platform {
     std::filesystem::path get_executable_path();
     /// @brief Run a separate engine instance with specified arguments
     void new_engine_instance(
-        const std::vector<std::string>& args, std::filesystem::path outputFile
+        const std::vector<std::string>& args,
+        std::filesystem::path outputFile,
+        bool subProcess
     );
     /// @brief Open URL in web browser 
     bool open_url(const std::string& url);