--- Lib/subprocess.py	2004-11-07 15:30:34.000000000 +0100
+++ /home/mattias/bugs/subprocess.py	2005-04-22 18:03:48.000000000 +0200
@@ -50,7 +50,7 @@
             stdin=None, stdout=None, stderr=None,
             preexec_fn=None, close_fds=False, shell=False,
             cwd=None, env=None, universal_newlines=False,
-            startupinfo=None, creationflags=0):
+            startupinfo=None, creationflags=0, autowait=True):
 
 
 Arguments are:
@@ -122,6 +122,16 @@
 appearance of the main window and priority for the new process.
 (Windows only)
 
+If autowait is true or omitted, then the new process will be waited
+for automatically if it has terminated when another Popen instance is
+created. This is done to keep too many zombie processes from lingering
+in the system. If false, then the user is responsible for waiting for
+the process (retrieving its exit status from the operating system),
+either using the poll(), wait() or communicate() methods or the
+os.wait()/os.waitpid() functions. In order to use os.wait() or
+os.waitpid() with the process ID of the created process, autowait
+should be set to false.
+
 
 This module also defines two shortcut functions:
 
@@ -237,7 +247,7 @@
 ---------------------
 sts = os.system("mycmd" + " myarg")
 ==>
-p = Popen("mycmd" + " myarg", shell=True)
+p = Popen("mycmd" + " myarg", shell=True, autowait=False)
 sts = os.waitpid(p.pid, 0)
 
 Note:
@@ -245,7 +255,7 @@
 * Calling the program through the shell is usually not required.
 
 * It's easier to look at the returncode attribute than the
-  exitstatus.
+  exit status.
 
 A more real-world example would look like this:
 
@@ -289,6 +299,11 @@
 Popen(["/bin/mycmd", "myarg"], env={"PATH": "/usr/bin"})
 
 
+Note: In order to use os.wait() or os.waitpid() with the process ID
+of the created Popen object, the autowait parameter should be set
+to False.
+
+
 Replacing os.popen*
 -------------------
 pipe = os.popen(cmd, mode='r', bufsize)
@@ -407,10 +422,10 @@
     False = 0
     True = 1
 
-_active = []
+_active = {}                       # set of instances to auto-wait for
 
 def _cleanup():
-    for inst in _active[:]:
+    for inst in _active.keys():
         inst.poll()
 
 PIPE = -1
@@ -500,7 +515,7 @@
                  stdin=None, stdout=None, stderr=None,
                  preexec_fn=None, close_fds=False, shell=False,
                  cwd=None, env=None, universal_newlines=False,
-                 startupinfo=None, creationflags=0):
+                 startupinfo=None, creationflags=0, autowait=True):
         """Create new Popen instance."""
         _cleanup()
 
@@ -566,7 +581,8 @@
             else:
                 self.stderr = os.fdopen(errread, 'rb', bufsize)
 
-        _active.append(self)
+        if autowait:
+            _active[self] = 1
 
 
     def _translate_newlines(self, data):
@@ -748,7 +764,7 @@
             if self.returncode == None:
                 if WaitForSingleObject(self._handle, 0) == WAIT_OBJECT_0:
                     self.returncode = GetExitCodeProcess(self._handle)
-                    _active.remove(self)
+                    del _active[self]
             return self.returncode
 
 
@@ -758,7 +774,7 @@
             if self.returncode == None:
                 obj = WaitForSingleObject(self._handle, INFINITE)
                 self.returncode = GetExitCodeProcess(self._handle)
-                _active.remove(self)
+                del _active[self]
             return self.returncode
 
 
@@ -995,7 +1011,7 @@
                 # Should never happen
                 raise RuntimeError("Unknown child exit status!")
 
-            _active.remove(self)
+            del _active[self]
 
 
         def poll(self):