Merge with 3.1

Lib/test/test_subprocess.py

@@ -1226,6 +1226,7 @@ class POSIXProcessTestCase(BaseTestCase):
                              stdout=subprocess.PIPE,
                              bufsize=0)
         f = p.stdout
+        self.addCleanup(f.close)
         try:
             self.assertEqual(f.read(4), b"appl")
             self.assertIn(f, select.select([f], [], [], 0.0)[0])

Misc/ACKS

@@ -354,6 +354,7 @@ Brian Harring
 Larry Hastings
 Shane Hathaway
 Rycharde Hawkes
+Ben Hayden
 Jochen Hayek
 Christian Heimes
 Thomas Heller

Misc/NEWS

@@ -53,6 +53,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #11659: Fix ResourceWarning in test_subprocess introduced by #11459.
+  Patch by Ben Hayden.
+
 - Issue #11635: Don't use polling in worker threads and processes launched by
   concurrent.futures.