[Python-checkins] [3.9] bpo-44482: Fix very unlikely resource leak in glob in non-CPython implementations (GH-26843). (GH-26916)

[serhiy-storchaka]

https://github.com/python/cpython/commit/4861fdaf25f246eb9ee4e8161c15dad26efe895d
commit: 4861fdaf25f246eb9ee4e8161c15dad26efe895d
branch: 3.9
author: Serhiy Storchaka <storchaka at gmail.com>
committer: serhiy-storchaka <storchaka at gmail.com>
date: 2021-06-27T14:28:24+03:00
summary:

[3.9] bpo-44482: Fix very unlikely resource leak in glob in non-CPython implementations (GH-26843). (GH-26916)

(cherry picked from commit 5c7940257e1f611e7284fd504887bd29a63d0a94)

files:
A Misc/NEWS.d/next/Library/2021-06-22-08-43-04.bpo-44482.U9GznK.rst
M Lib/glob.py

diff --git a/Lib/glob.py b/Lib/glob.py
index 0dd2f8be66109..1237061130951 100644
--- a/Lib/glob.py
+++ b/Lib/glob.py
@@ -1,5 +1,6 @@
 """Filename globbing utility."""
 
+import contextlib
 import os
 import re
 import fnmatch
@@ -79,7 +80,7 @@ def _iglob(pathname, recursive, dironly):
 # takes a literal basename (so it only has to check for its existence).
 
 def _glob1(dirname, pattern, dironly):
-    names = list(_iterdir(dirname, dironly))
+    names = _listdir(dirname, dironly)
     if not _ishidden(pattern):
         names = (x for x in names if not _ishidden(x))
     return fnmatch.filter(names, pattern)
@@ -130,9 +131,13 @@ def _iterdir(dirname, dironly):
     except OSError:
         return
 
+def _listdir(dirname, dironly):
+    with contextlib.closing(_iterdir(dirname, dironly)) as it:
+        return list(it)
+
 # Recursively yields relative pathnames inside a literal directory.
 def _rlistdir(dirname, dironly):
-    names = list(_iterdir(dirname, dironly))
+    names = _listdir(dirname, dironly)
     for x in names:
         if not _ishidden(x):
             yield x
diff --git a/Misc/NEWS.d/next/Library/2021-06-22-08-43-04.bpo-44482.U9GznK.rst b/Misc/NEWS.d/next/Library/2021-06-22-08-43-04.bpo-44482.U9GznK.rst
new file mode 100644
index 0000000000000..d05fe908e3eba
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-06-22-08-43-04.bpo-44482.U9GznK.rst
@@ -0,0 +1,2 @@
+Fix very unlikely resource leak in :mod:`glob` in alternate Python
+implementations.