--- py3k/Lib/subprocess.py	2010-12-10 20:09:56.000000000 +0200
+++ py3k-subprocess/Lib/subprocess.py	2010-12-10 20:35:13.000000000 +0200
@@ -609,7 +609,7 @@
                  cwd=None, env=None, universal_newlines=False,
                  startupinfo=None, creationflags=0,
                  restore_signals=True, start_new_session=False,
-                 pass_fds=()):
+                 pass_fds=(), pipes_cloexec=True):
         """Create new Popen instance."""
         _cleanup()
 
@@ -675,7 +675,7 @@
          errread, errwrite) = self._get_handles(stdin, stdout, stderr)
 
         self._execute_child(args, executable, preexec_fn, close_fds,
-                            pass_fds, cwd, env, universal_newlines,
+                            pass_fds, pipes_cloexec, cwd, env, universal_newlines,
                             startupinfo, creationflags, shell,
                             p2cread, p2cwrite,
                             c2pread, c2pwrite,
@@ -852,7 +852,7 @@
 
 
         def _execute_child(self, args, executable, preexec_fn, close_fds,
-                           pass_fds, cwd, env, universal_newlines,
+                           pass_fds, pipes_cloexec, cwd, env, universal_newlines,
                            startupinfo, creationflags, shell,
                            p2cread, p2cwrite,
                            c2pread, c2pwrite,
@@ -1093,7 +1093,7 @@
 
 
         def _execute_child(self, args, executable, preexec_fn, close_fds,
-                           pass_fds, cwd, env, universal_newlines,
+                           pass_fds, pipes_cloexec, cwd, env, universal_newlines,
                            startupinfo, creationflags, shell,
                            p2cread, p2cwrite,
                            c2pread, c2pwrite,
@@ -1262,10 +1262,16 @@
                     os.close(errpipe_write)
 
                 if p2cread != -1 and p2cwrite != -1:
+                    if pipes_cloexec:
+                        self._set_cloexec_flag(p2cwrite)
                     os.close(p2cread)
                 if c2pwrite != -1 and c2pread != -1:
+                    if pipes_cloexec:
+                        self._set_cloexec_flag(c2pread)
                     os.close(c2pwrite)
                 if errwrite != -1 and errread != -1:
+                    if pipes_cloexec:
+                        self._set_cloexec_flag(errread)
                     os.close(errwrite)
 
                 # Wait for exec to fail or succeed; possibly raising an