From ad5ae988ac55262483951f5e70b1521af7e423e7 Mon Sep 17 00:00:00 2001
From: Xiang Zhang <angwerzx@126.com>
Date: Mon, 27 Feb 2017 11:01:30 +0800
Subject: [PATCH] fix bpo-29376

---
 Lib/test/test_threading.py | 3 +++
 Lib/threading.py           | 4 ++++
 Misc/NEWS                  | 2 ++
 3 files changed, 9 insertions(+)

diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index b63050982ab694..83a99023d7a8ae 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -170,6 +170,9 @@ def f(mutex):
         mutex.acquire()
         self.assertIn(tid, threading._active)
         self.assertIsInstance(threading._active[tid], threading._DummyThread)
+        #Issue 29376
+        self.assertTrue(threading._active[tid].is_alive())
+        self.assertRegex(repr(threading._active[tid]), '_DummyThread')
         del threading._active[tid]
 
     # PyThreadState_SetAsyncExc() is a CPython-only gimmick, not (currently)
diff --git a/Lib/threading.py b/Lib/threading.py
index 06b7b9b4fac598..c40d3307b2f265 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -1215,6 +1215,10 @@ def __init__(self):
     def _stop(self):
         pass
 
+    def is_alive(self):
+        assert not self._is_stopped and self._started.is_set()
+        return True
+
     def join(self, timeout=None):
         assert False, "cannot join a dummy thread"
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 8a7e1b5cd9c16e..635f413dc74be8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -32,6 +32,8 @@ Extension Modules
 Library
 -------
 
+- bpo-29376: Fix assertion error in threading._DummyThread.is_alive().
+
 - bpo-29110: Fix file object leak in aifc.open() when file is given as a
   filesystem path and is not in valid AIFF format. Patch by Anthony Zhang.