From b720f3ef6d462b99840f2ade3415ba655eca7090 Mon Sep 17 00:00:00 2001
From: user202729 <25191436+user202729@users.noreply.github.com>
Date: Sat, 19 Apr 2025 01:57:34 +0700
Subject: [PATCH] Restore OS-level signal handler

---
 lib/matplotlib/backend_bases.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
index 2158990f578a..88cf832a04c6 100644
--- a/lib/matplotlib/backend_bases.py
+++ b/lib/matplotlib/backend_bases.py
@@ -42,6 +42,7 @@
 import time
 import weakref
 from weakref import WeakKeyDictionary
+from ctypes import c_int, c_void_p, pythonapi
 
 import numpy as np
 
@@ -59,6 +60,11 @@
 from matplotlib._enums import JoinStyle, CapStyle
 
 
+pythonapi.PyOS_getsig.restype = c_void_p
+pythonapi.PyOS_getsig.argtypes = (c_int,)
+pythonapi.PyOS_setsig.restype = c_void_p
+pythonapi.PyOS_setsig.argtypes = (c_int, c_void_p)
+
 _log = logging.getLogger(__name__)
 _default_filetypes = {
     'eps': 'Encapsulated Postscript',
@@ -1655,6 +1661,10 @@ def _allow_interrupt(prepare_notifier, handle_sigint):
     old_wakeup_fd = signal.set_wakeup_fd(wsock.fileno())
     notifier = prepare_notifier(rsock)
 
+    # Save OS level sigint handlers
+    # See https://github.com/prompt-toolkit/python-prompt-toolkit/issues/1576
+    sigint_os = pythonapi.PyOS_getsig(signal.SIGINT)
+
     def save_args_and_handle_sigint(*args):
         nonlocal handler_args
         handler_args = args
@@ -1668,6 +1678,7 @@ def save_args_and_handle_sigint(*args):
         rsock.close()
         signal.set_wakeup_fd(old_wakeup_fd)
         signal.signal(signal.SIGINT, old_sigint_handler)
+        pythonapi.PyOS_setsig(signal.SIGINT, sigint_os)
         if handler_args is not None:
             old_sigint_handler(*handler_args)