Merge with 3.1
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 01e670e..7ca3d92 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -1226,6 +1226,7 @@
                              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])