bpo-34044: subprocess.Popen copies startupinfo (GH-8090) (GH-8121)
subprocess.Popen now copies the startupinfo argument to leave it
unchanged: it will modify the copy, so that the same STARTUPINFO
object can be used multiple times.
Add subprocess.STARTUPINFO._copy() private method.
Python 3.7 backport from master makes the copy() private: renamed to
_copy().
(cherry picked from commit 483422f57e5d8c8bf8820fec29fc9b96bb15d4ef)
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 4b089f5..73b57b2 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -2822,6 +2822,33 @@
subprocess.call([sys.executable, "-c", "import sys; sys.exit(0)"],
startupinfo=startupinfo)
+ def test_startupinfo_copy(self):
+ # bpo-34044: Popen must not modify input STARTUPINFO structure
+ startupinfo = subprocess.STARTUPINFO()
+ startupinfo.dwFlags = subprocess.STARTF_USESHOWWINDOW
+ startupinfo.wShowWindow = subprocess.SW_HIDE
+
+ # Call Popen() twice with the same startupinfo object to make sure
+ # that it's not modified
+ for _ in range(2):
+ cmd = [sys.executable, "-c", "pass"]
+ with open(os.devnull, 'w') as null:
+ proc = subprocess.Popen(cmd,
+ stdout=null,
+ stderr=subprocess.STDOUT,
+ startupinfo=startupinfo)
+ with proc:
+ proc.communicate()
+ self.assertEqual(proc.returncode, 0)
+
+ self.assertEqual(startupinfo.dwFlags,
+ subprocess.STARTF_USESHOWWINDOW)
+ self.assertIsNone(startupinfo.hStdInput)
+ self.assertIsNone(startupinfo.hStdOutput)
+ self.assertIsNone(startupinfo.hStdError)
+ self.assertEqual(startupinfo.wShowWindow, subprocess.SW_HIDE)
+ self.assertEqual(startupinfo.lpAttributeList, {"handle_list": []})
+
def test_creationflags(self):
# creationflags argument
CREATE_NEW_CONSOLE = 16