From 02bad367d6af8c3c08b594575600e4dd996c9c69 Mon Sep 17 00:00:00 2001
From: Xia Jiang <xia.jiang.code@outlook.com>
Date: Mon, 26 Oct 2026 09:54:39 +0800
Subject: [PATCH] gh-160683: Stop half-closing the remote debugging interrupt
 socket

---
 Lib/pdb.py                                    |  1 -
 Lib/test/test_remote_pdb.py                   | 35 +++++++++++++++++++
 ...-10-26-03-58-12.gh-issue-160683.Kz3q1P.rst |  5 +++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2026-10-26-03-58-12.gh-issue-160683.Kz3q1P.rst

diff --git a/Lib/pdb.py b/Lib/pdb.py
index 114634a4469c131..2b90bb3284e62d1 100644
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -3006,7 +3006,6 @@ def listener(sock):
                 # Check if the interpreter is finalizing every quarter of a second.
                 # Clean up and exit if so.
                 sock.settimeout(0.25)
-                sock.shutdown(socket.SHUT_WR)
                 while not shut_down.is_set():
                     try:
                         data = sock.recv(1024)
diff --git a/Lib/test/test_remote_pdb.py b/Lib/test/test_remote_pdb.py
index e5387526090536d..87dcbcdf29bc4b2 100644
--- a/Lib/test/test_remote_pdb.py
+++ b/Lib/test/test_remote_pdb.py
@@ -835,6 +835,41 @@ def test_reading_empty_json_during_completion(self):
         )
 
 
+@requires_subprocess()
+class SignalListenerTestCase(unittest.TestCase):
+    def test_interrupt_socket_is_not_half_closed(self):
+        # gh-160683: half-closing leaves the connection in FIN_WAIT_2, which
+        # Windows tears down after 120 seconds, so a session that has been
+        # idle that long loses its interrupt channel.
+        # The listener thread is kept alive by an atexit callback and cannot be
+        # joined, so start it in a subprocess to leave this interpreter's
+        # thread bookkeeping untouched.
+        with closing(socket.socket()) as listener:
+            listener.bind(("127.0.0.1", 0))
+            listener.listen(1)
+            listener.settimeout(SHORT_TIMEOUT)
+            code = textwrap.dedent(f"""
+                import sys
+                from pdb import _PdbServer
+
+                _PdbServer._start_signal_listener({listener.getsockname()})
+                sys.stdin.read()
+            """)
+            with subprocess.Popen(
+                [sys.executable, "-c", code], stdin=subprocess.PIPE
+            ) as process:
+                with closing(listener.accept()[0]) as conn:
+                    conn.settimeout(1.0)
+                    try:
+                        data = conn.recv(1024)
+                    except TimeoutError:
+                        pass
+                    else:
+                        self.fail(
+                            f"interrupt socket returned {data!r} instead of staying open"
+                        )
+
+
 class RemotePdbTestCase(unittest.TestCase):
     """Tests for the _PdbServer class."""
 
diff --git a/Misc/NEWS.d/next/Library/2026-10-26-03-58-12.gh-issue-160683.Kz3q1P.rst b/Misc/NEWS.d/next/Library/2026-10-26-03-58-12.gh-issue-160683.Kz3q1P.rst
new file mode 100644
index 000000000000000..5903e0eedeb8828
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-10-26-03-58-12.gh-issue-160683.Kz3q1P.rst
@@ -0,0 +1,5 @@
+Keep the interrupt channel of a remote debugging session open.
+
+Half-closing it left the connection in FIN_WAIT_2, which Windows resets
+after 120 seconds, so an idle session silently lost the ability to
+interrupt the debuggee.