From 1fd497ed91a14eabaf37e9b3f17dde8c3169ef25 Mon Sep 17 00:00:00 2001
From: Berker Peksag <berker.peksag@gmail.com>
Date: Sat, 23 Jul 2016 07:13:14 +0300
Subject: [PATCH] Issue #27591: Set sigint_event to NULL if
 _PyOS_IsMainThread() returns false

Patch by Chris Angelico.
---
 Modules/_multiprocessing/semaphore.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Modules/_multiprocessing/semaphore.c b/Modules/_multiprocessing/semaphore.c
index de85a90d472..cea962ab26c 100644
--- a/Modules/_multiprocessing/semaphore.c
+++ b/Modules/_multiprocessing/semaphore.c
@@ -114,6 +114,9 @@ semlock_acquire(SemLockObject *self, PyObject *args, PyObject *kwds)
         assert(sigint_event != NULL);
         handles[nhandles++] = sigint_event;
     }
+    else {
+        sigint_event = NULL;
+    }
 
     /* do the wait */
     Py_BEGIN_ALLOW_THREADS