From a8827f0ef462cb39bd643c07910bb06c0678b6f6 2015-02-05 19:11:40
From: Thomas Kluyver <takowl@gmail.com>
Date: 2015-02-05 19:11:40
Subject: [PATCH] Merge pull request #7688 from minrk/callable-interrupt

check if SIGINT handler is callable before triggering it
---

diff --git a/IPython/kernel/zmq/parentpoller.py b/IPython/kernel/zmq/parentpoller.py
index b745b02..d623f9d 100644
--- a/IPython/kernel/zmq/parentpoller.py
+++ b/IPython/kernel/zmq/parentpoller.py
@@ -1,10 +1,13 @@
-# Standard library imports.
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+
 try:
     import ctypes
 except:
     ctypes = None
 import os
 import platform
+import signal
 import time
 try:
     from _thread import interrupt_main  # Py 3
@@ -129,7 +132,10 @@ class ParentPollerWindows(Thread):
                 handle = handles[result - WAIT_OBJECT_0]
 
                 if handle == self.interrupt_handle:
-                    interrupt_main()
+                    # check if signal handler is callable
+                    # to avoid 'int not callable' error (Python issue #23395)
+                    if callable(signal.getsignal(signal.SIGINT)):
+                        interrupt_main()
 
                 elif handle == self.parent_handle:
                     os._exit(1)