Index: Lib/test/test_subprocess.py
===================================================================
--- Lib/test/test_subprocess.py	(revision 62996)
+++ Lib/test/test_subprocess.py	(working copy)
@@ -608,6 +608,58 @@
             p.terminate()
             self.assertEqual(p.wait(), -signal.SIGTERM)
 
+        def test_remapping_std_fds(self):
+            # open up some temporary files
+            temps = (self.mkstemp(), self.mkstemp(), self.mkstemp())
+            try:
+                temp_fds = [ fd for fd, fname in temps ]
+
+                # unlink the files -- we won't need to reopen them
+                for fd, fname in temps:
+                    os.unlink(fname)
+
+                # write some data to what will become stdin, and rewind
+                os.write(temp_fds[1], "STDIN")
+                os.lseek(temp_fds[1], 0, 0)
+
+                # move the standard file descriptors out of the way 
+                std_fds = (0,1,2)
+                saved_fds = [ os.dup(fd) for fd in std_fds ]
+                try:
+                    # duplicate the file objects over the standard fd's
+                    for fd in std_fds:
+                        os.dup2(temp_fds[fd], fd)
+
+                    # and create corresponding file objects
+                    new_std_files = [ os.fdopen(fd, "rw") for fd in std_fds ]
+
+                    # now use those files in the "wrong" order, so that subprocess has to
+                    # rearrange them in the child
+                    p = subprocess.Popen([sys.executable, "-c",
+                        'import sys; got = sys.stdin.read(); sys.stdout.write("got %s"%got); sys.stderr.write("err")'],
+                        stdin=new_std_files[1],
+                        stdout=new_std_files[2],
+                        stderr=new_std_files[0])
+                    p.wait()
+
+                finally:
+                    del new_std_files # close file objects at std_fds
+
+                    # restore the original fd's underneath sys.stdin, etc.
+                    for saved, std in zip(saved_fds, std_fds):
+                        os.dup2(saved, std)
+                        os.close(saved)
+                    
+                for fd in temp_fds:
+                    os.lseek(fd, 0, 0)
+
+                self.assertEqual(os.read(temp_fds[0], 1024), "err")
+                self.assertEqual(os.read(temp_fds[2], 1024), "got STDIN")
+
+            finally:
+                for fd in temp_fds:
+                    os.close(fd)
+
     #
     # Windows tests
     #
Index: Lib/subprocess.py
===================================================================
--- Lib/subprocess.py	(revision 62996)
+++ Lib/subprocess.py	(working copy)
@@ -1035,22 +1035,36 @@
                         os.close(errread)
                     os.close(errpipe_read)
 
-                    # Dup fds for child
+                    # Dup fds for child, making sure not to overwrite any
+		    # of the given fd's while we're at it.
                     if p2cread is not None:
+			if c2pwrite == 0:
+			    c2pwrite = os.dup(c2pwrite)
+			if errwrite == 0:
+			    errwrite = os.dup(errwrite) 
                         os.dup2(p2cread, 0)
                     if c2pwrite is not None:
+			if errwrite == 1:
+			    errwrite = os.dup(errwrite)
+			if errpipe_write == 1:
+			    errpipe_write = os.dup(errpipe_write)
+			    self._set_cloexec_flag(errpipe_write)
                         os.dup2(c2pwrite, 1)
                     if errwrite is not None:
+			if errpipe_write == 2:
+			    errpipe_write = os.dup(errpipe_write)
+			    self._set_cloexec_flag(errpipe_write)
                         os.dup2(errwrite, 2)
 
                     # Close pipe fds.  Make sure we don't close the same
                     # fd more than once, or standard fds.
-                    if p2cread is not None and p2cread not in (0,):
-                        os.close(p2cread)
-                    if c2pwrite is not None and c2pwrite not in (p2cread, 1):
-                        os.close(c2pwrite)
-                    if errwrite is not None and errwrite not in (p2cread, c2pwrite, 2):
-                        os.close(errwrite)
+		    dup_fds = { p2cread       : None,
+				c2pwrite      : None,
+				errwrite      : None,
+			      }
+		    for fd in dup_fds:
+			if fd not in (0, 1, 2, None):
+			    os.close(fd)
 
                     # Close all other fds, if asked for
                     if close_fds: