From 7cfab1a30559bf5da4efafc66112da3b46aa1e5b Mon Sep 17 00:00:00 2001
From: Aurel Wildfellner <201101774+aurelwildfellner@users.noreply.github.com>
Date: Thu, 5 Mar 2026 13:44:17 +0100
Subject: [PATCH 1/2] Add test_unclosed_interpreter_on_fork to cover gh-139759

---
 Lib/test/test_interpreters/test_stress.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/Lib/test/test_interpreters/test_stress.py b/Lib/test/test_interpreters/test_stress.py
index 56bfc12f951f79..30b84aa323bd2d 100644
--- a/Lib/test/test_interpreters/test_stress.py
+++ b/Lib/test/test_interpreters/test_stress.py
@@ -1,3 +1,4 @@
+import os
 import threading
 import unittest
 
@@ -82,6 +83,24 @@ def test_create_interpreter_no_memory(self):
             with support.inject_memory_error_cm(0, 1):
                 _interpreters.create()
 
+    @support.requires_fork()
+    def test_unclosed_interpreter_on_fork(self):
+        interp = interpreters.create()
+        interp.exec("pass")
+
+        fds = os.pipe()
+        pid = os.fork()
+
+        if pid == 0:
+            os.close(fds[0])
+            os.write(fds[1], b"OK")
+            os._exit(0)
+        else:
+            os.close(fds[1])
+            self.addCleanup(os.close, fds[0])
+            value = os.read(fds[0], 100)
+            self.assertEqual(value, b"OK")
+
 
 if __name__ == '__main__':
     # Test needs to be a package, so we can do relative imports.

From 1fdc86af06cff03503cae6a042c4179d38ff260d Mon Sep 17 00:00:00 2001
From: Aurel Wildfellner <201101774+aurelwildfellner@users.noreply.github.com>
Date: Fri, 23 Oct 2026 15:09:27 +0200
Subject: [PATCH 2/2] add ignore_fork_in_thread_deprecation_warnings()
 decorator to test.

---
 Lib/test/test_interpreters/test_stress.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Lib/test/test_interpreters/test_stress.py b/Lib/test/test_interpreters/test_stress.py
index 30b84aa323bd2d..a3689a2acb9336 100644
--- a/Lib/test/test_interpreters/test_stress.py
+++ b/Lib/test/test_interpreters/test_stress.py
@@ -5,6 +5,7 @@
 from test import support
 from test.support import import_helper
 from test.support import threading_helper
+from test.support import warnings_helper
 # Raise SkipTest if subinterpreters not supported.
 _interpreters = import_helper.import_module('_interpreters')
 from concurrent import interpreters
@@ -83,6 +84,7 @@ def test_create_interpreter_no_memory(self):
             with support.inject_memory_error_cm(0, 1):
                 _interpreters.create()
 
+    @warnings_helper.ignore_fork_in_thread_deprecation_warnings()
     @support.requires_fork()
     def test_unclosed_interpreter_on_fork(self):
         interp = interpreters.create()