bpo-35182: fix communicate() crash after child closes its pipes (GH-17020) (GH-18117)
When communicate() is called in a loop, it crashes when the child process
has already closed any piped standard stream, but still continues to be running
Co-authored-by: Andriy Maletsky <andriy.maletsky@gmail.com>
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index f1fb934..2bbdbae 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -3145,6 +3145,17 @@
# so Popen failed to read it and uses a default returncode instead.
self.assertIsNotNone(proc.returncode)
+ def test_communicate_repeated_call_after_stdout_close(self):
+ proc = subprocess.Popen([sys.executable, '-c',
+ 'import os, time; os.close(1), time.sleep(2)'],
+ stdout=subprocess.PIPE)
+ while True:
+ try:
+ proc.communicate(timeout=0.1)
+ return
+ except subprocess.TimeoutExpired:
+ pass
+
@unittest.skipUnless(mswindows, "Windows specific tests")
class Win32ProcessTestCase(BaseTestCase):