Index: Misc/NEWS
===================================================================
--- Misc/NEWS	(revision 87602)
+++ Misc/NEWS	(working copy)
@@ -20,6 +20,9 @@
 Library
 -------
 
+- Issue 9905: In subprocess, don't close standard file descriptors. Patch
+  by Ross Lagerwall.
+
 - Issue 6285: IDLE no longer crashes on missing help file; patch by Scott David
   Daniels.
 
Index: Lib/test/test_subprocess.py
===================================================================
--- Lib/test/test_subprocess.py	(revision 87602)
+++ Lib/test/test_subprocess.py	(working copy)
@@ -897,6 +897,27 @@
         self.assertStderrEqual(stderr, b'')
         self.assertEqual(p.wait(), -signal.SIGKILL)
 
+    def test_issue9905(self):
+        o0 = os.dup(0)
+        o2 = os.dup(2)
+        try:
+            os.close(0)
+            os.close(2)
+            res = subprocess.Popen([sys.executable, "-c",
+                              'import sys;'
+                              'sys.stdout.write("apple");'
+                              'sys.stdout.flush();'
+                              'sys.stderr.write("orange")'],
+                       stdin=o0,
+                       stdout=subprocess.PIPE,
+                       stderr=subprocess.PIPE).communicate()
+            self.assertEqual(res, (b'apple', b'orange'))
+        finally:
+            os.dup2(o0, 0)
+            os.dup2(o2, 2)
+            os.close(o0)
+            os.close(o2)
+
     def test_terminate(self):
         p = self._kill_process('terminate')
         _, stderr = p.communicate()
Index: Lib/subprocess.py
===================================================================
--- Lib/subprocess.py	(revision 87602)
+++ Lib/subprocess.py	(working copy)
@@ -1203,13 +1203,13 @@
 
                                 # Close pipe fds.  Make sure we don't close the
                                 # same fd more than once, or standard fds.
-                                if p2cread != -1 and p2cread not in (0,):
+                                if p2cread != -1 and p2cread not in (0, 1, 2):
                                     os.close(p2cread)
                                 if (c2pwrite != -1 and
-                                    c2pwrite not in (p2cread, 1)):
+                                    c2pwrite not in (p2cread, 0, 1, 2)):
                                     os.close(c2pwrite)
                                 if (errwrite != -1 and
-                                    errwrite not in (p2cread, c2pwrite, 2)):
+                                    errwrite not in (p2cread, c2pwrite, 0, 1, 2)):
                                     os.close(errwrite)
 
                                 # Close all other fds, if asked for
Index: Modules/_posixsubprocess.c
===================================================================
--- Modules/_posixsubprocess.c	(revision 87602)
+++ Modules/_posixsubprocess.c	(working copy)
@@ -82,14 +82,16 @@
 
     /* Close pipe fds.  Make sure we don't close the same fd more than */
     /* once, or standard fds. */
-    if (p2cread != -1 && p2cread != 0) {
+    if (p2cread != -1 && p2cread != 0 && p2cread != 1 && p2cread != 2) {
         POSIX_CALL(close(p2cread));
     }
-    if (c2pwrite != -1 && c2pwrite != p2cread && c2pwrite != 1) {
+    if (c2pwrite != -1 && c2pwrite != p2cread && c2pwrite != 0 &&
+            c2pwrite != 1 && c2pwrite != 2) {
         POSIX_CALL(close(c2pwrite));
     }
     if (errwrite != -1 && errwrite != p2cread &&
-        errwrite != c2pwrite && errwrite != 2) {
+            errwrite != c2pwrite && errwrite != 0 &&
+            errwrite != 1 &&errwrite != 2) {
         POSIX_CALL(close(errwrite));
     }