[Python-checkins] cpython: - Issue #12044: Fixed subprocess.Popen when used as a context manager to

[gregory.p.smith]

http://hg.python.org/cpython/rev/7a3f3ad83676
changeset:   70048:7a3f3ad83676
user:        Gregory P. Smith <greg at krypto.org>
date:        Wed May 11 21:42:08 2011 -0700
summary:
  - Issue #12044: Fixed subprocess.Popen when used as a context manager to
  wait for the process to end when exiting the context to avoid unintentionally
  leaving zombie processes around.

files:
  Doc/library/subprocess.rst  |  4 ++--
  Lib/subprocess.py           |  2 ++
  Lib/test/test_subprocess.py |  3 ++-
  Misc/NEWS                   |  4 ++++
  4 files changed, 10 insertions(+), 3 deletions(-)


diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -219,8 +219,8 @@
    *creationflags*, if given, can be :data:`CREATE_NEW_CONSOLE` or
    :data:`CREATE_NEW_PROCESS_GROUP`. (Windows only)
 
-   Popen objects are supported as context managers via the :keyword:`with` statement,
-   closing any open file descriptors on exit.
+   Popen objects are supported as context managers via the :keyword:`with` statement:
+   on exit, standard file descriptors are closed, and the process is waited for.
    ::
 
       with Popen(["ifconfig"], stdout=PIPE) as proc:
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -796,6 +796,8 @@
             self.stderr.close()
         if self.stdin:
             self.stdin.close()
+        # Wait for the process to terminate, to avoid zombies.
+        self.wait()
 
     def __del__(self, _maxsize=sys.maxsize, _active=_active):
         if not self._child_created:
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -1590,7 +1590,8 @@
     def test_returncode(self):
         with subprocess.Popen([sys.executable, "-c",
                                "import sys; sys.exit(100)"]) as proc:
-            proc.wait()
+            pass
+        # __exit__ calls wait(), so the returncode should be set
         self.assertEqual(proc.returncode, 100)
 
     def test_communicate_stdin(self):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
 Core and Builtins
 -----------------
 
+- Issue #12044: Fixed subprocess.Popen when used as a context manager to
+  wait for the process to end when exiting the context to avoid unintentionally
+  leaving zombie processes around.
+
 - Issue #1195: Fix input() if it is interrupted by CTRL+d and then CTRL+c,
   clear the end-of-file indicator after CTRL+d.
 

-- 
Repository URL: http://hg.python.org/cpython