Issue #11459: A `bufsize` value of 0 in subprocess.Popen() really creates
unbuffered pipes, such that select() works properly on them.
diff --git a/Doc/library/platform.rst b/Doc/library/platform.rst
index 56518f7..a71d533 100644
--- a/Doc/library/platform.rst
+++ b/Doc/library/platform.rst
@@ -205,7 +205,7 @@
Win95/98 specific
^^^^^^^^^^^^^^^^^
-.. function:: popen(cmd, mode='r', bufsize=None)
+.. function:: popen(cmd, mode='r', bufsize=-1)
Portable :func:`popen` interface. Find a working popen implementation
preferring :func:`win32pipe.popen`. On Windows NT, :func:`win32pipe.popen`