diff -ruN py3k-subprocess2/Lib/test/subprocessdata/fd_status.py py3k-subprocess2-unittest/Lib/test/subprocessdata/fd_status.py
--- py3k-subprocess2/Lib/test/subprocessdata/fd_status.py	1970-01-01 02:00:00.000000000 +0200
+++ py3k-subprocess2-unittest/Lib/test/subprocessdata/fd_status.py	2010-12-11 13:14:34.000000000 +0200
@@ -0,0 +1,21 @@
+import errno
+import os
+import fcntl
+
+try:
+    _MAXFD = os.sysconf("SC_OPEN_MAX")
+except:
+    _MAXFD = 256
+
+def isopen(fd):
+    try:
+        fcntl.fcntl(fd, fcntl.F_GETFD, 0)
+    except IOError as e:
+        if e.errno == errno.EBADF:
+            return False
+        raise
+    return True
+
+if __name__ == "__main__":
+    print(','.join(str(fd) for fd in range(0, _MAXFD) if isopen(fd)))
+    
diff -ruN py3k-subprocess2/Lib/test/subprocessdata/input_reader.py py3k-subprocess2-unittest/Lib/test/subprocessdata/input_reader.py
--- py3k-subprocess2/Lib/test/subprocessdata/input_reader.py	1970-01-01 02:00:00.000000000 +0200
+++ py3k-subprocess2-unittest/Lib/test/subprocessdata/input_reader.py	2010-12-11 14:17:13.000000000 +0200
@@ -0,0 +1,5 @@
+import sys
+
+if __name__ = "__main__":
+    for line in sys.stdin:
+        pass
diff -ruN py3k-subprocess2/Lib/test/test_subprocess.py py3k-subprocess2-unittest/Lib/test/test_subprocess.py
--- py3k-subprocess2/Lib/test/test_subprocess.py	2010-12-10 20:09:56.000000000 +0200
+++ py3k-subprocess2-unittest/Lib/test/test_subprocess.py	2010-12-11 14:42:27.000000000 +0200
@@ -10,6 +10,7 @@
 import re
 import sysconfig
 import warnings
+import select
 try:
     import gc
 except ImportError:
@@ -980,6 +981,69 @@
         exitcode = subprocess.call([program, "-c", "pass"], env=envb)
         self.assertEqual(exitcode, 0)
 
+    def test_pipe_cloexec(self):
+        sleeper = support.findfile("input_reader.py", subdir="subprocessdata")
+        fd_status = support.findfile("fd_status.py", subdir="subprocessdata")
+
+        p1 = subprocess.Popen([sys.executable, sleeper],
+                              stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                              stderr=subprocess.PIPE, close_fds=False)
+
+        self.addCleanup(p1.communicate, b'')
+
+        p2 = subprocess.Popen([sys.executable, fd_status],
+                              stdout=subprocess.PIPE, close_fds=False)
+
+        output, error = p2.communicate()
+        result_fds = set(map(int, output.split(b',')))
+        unwanted_fds = set([p1.stdin.fileno(), p1.stdout.fileno(), 
+                            p1.stderr.fileno()])
+
+        self.assertFalse(result_fds & unwanted_fds,
+                         "Expected no fds from %r to be open in child, "
+                         "found %r" % 
+                              (unwanted_fds, result_fds & unwanted_fds))
+
+    def test_pipe_cloexec_unix_tools(self):
+        utils = {}
+
+        path = os.environ['PATH']
+        prefixes = path.split(os.pathsep)
+        cat_candidates = (os.path.join(pfx, "cat") for pfx in prefixes)
+        grep_candidates = (os.path.join(pfx, "grep") for pfx in prefixes)
+
+        cat = next((f for f in cat_candidates if os.path.isfile(f)), None)
+        grep = next((f for f in grep_candidates if os.path.isfile(f)), None)
+        
+        if cat is None or grep is None:
+            self.skipTest("cat and grep are required for this test")
+
+        data = b'aaaaaaaaaaaaaaaaaaaa\n'
+        subdata = b'aaa'
+
+        assert subdata in data, "Test broken"
+
+        p1 = subprocess.Popen([cat], 
+                              stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                              close_fds=False)
+
+        p2 = subprocess.Popen([grep, 'a'],
+                              stdin=p1.stdout, stdout=subprocess.PIPE,
+                              close_fds=False)
+
+        self.addCleanup(p1.wait)
+        self.addCleanup(p2.wait)
+        self.addCleanup(p1.terminate)
+        self.addCleanup(p2.terminate)
+
+        p1.stdin.write(data)
+        p1.stdin.close()
+
+        readfiles, ignored1, ignored2 = select.select([p2.stdout], [], [], 10)
+
+        self.assertTrue(readfiles, "The child hung")
+        self.assertEqual(p2.stdout.read(), data)
+
 
 @unittest.skipUnless(mswindows, "Windows specific tests")
 class Win32ProcessTestCase(BaseTestCase):
diff -ruN py3k-subprocess2/Makefile.pre.in py3k-subprocess2-unittest/Makefile.pre.in
--- py3k-subprocess2/Makefile.pre.in	2010-12-10 20:09:57.000000000 +0200
+++ py3k-subprocess2-unittest/Makefile.pre.in	2010-12-11 14:08:25.000000000 +0200
@@ -888,7 +888,7 @@
 XMLLIBSUBDIRS=  xml xml/dom xml/etree xml/parsers xml/sax
 LIBSUBDIRS=	tkinter tkinter/test tkinter/test/test_tkinter \
                 tkinter/test/test_ttk site-packages test \
-		test/decimaltestdata test/xmltestdata \
+		test/decimaltestdata test/xmltestdata test/subprocessdata \
 		test/tracedmodules test/encoded_modules \
 		concurrent concurrent/futures encodings \
 		email email/mime email/test email/test/data \
diff -ruN py3k-subprocess2/Tools/msi/msi.py py3k-subprocess2-unittest/Tools/msi/msi.py
--- py3k-subprocess2/Tools/msi/msi.py	2010-12-10 20:09:46.000000000 +0200
+++ py3k-subprocess2-unittest/Tools/msi/msi.py	2010-12-11 14:09:21.000000000 +0200
@@ -1035,6 +1035,8 @@
         if dir=='xmltestdata':
             lib.glob("*.xml")
             lib.add_file("test.xml.out")
+        if dir=='subprocessdata':
+            lib.glob("*.py")
         if dir=='output':
             lib.glob("test_*")
         if dir=='sndhdrdata':