bug#3406: 23.0.91; bug in documentation of open-network-stream

the documentation of open-network-stream (as obtained
with C-h f (describe-function)) says:

"[...] buffer is the buffer (or buffer name) to associate with the process.
 Process output goes at end of that buffer, unless you specify
 an output stream or filter function to handle the output."

but:

'unless you specify an output stream or filter function'

it is not possible with open-network-stream to specify an output function
(this part of the documentation seems to be copied from
the documentation of the function make-network-process)

In GNU Emacs 23.0.91.1 (i486-pc-linux-gnu, GTK+ Version 2.12.11)
 of 2009-03-21 on elegiac, modified by Debian
 (emacs-snapshot package, version 1:20090320-1~lenny1)
Windowing system distributor `The X.Org Foundation', version 11.0.10402000
configured using `configure  '--build' 'i486-linux-gnu' '--host' 'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.91/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.91/site-lisp:/usr/share/emacs/site-lisp' '--with-x=yes' '--with-x-toolkit=gtk' 'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g -Wl,--as-needed' 'CPPFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Text

Minor modes in effect:
  diff-auto-refine-mode: t
  show-paren-mode: t
  display-time-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent input:
k - s t <tab> <tab> M-b M-b - <tab> <tab> C-e C-g C-h 
f o p e n <tab> n <tab> <return> C-x o C-n C-n C-n 
C-n C-SPC C-n C-n C-n C-g C-n C-n C-l C-n C-n C-n C-l 
C-p C-p C-p C-p C-n C-n C-n C-p C-SPC C-n C-n C-n C-n 
C-n M-w C-x o C-n C-o C-o C-o C-y C-p C-p C-p C-p C-p 
C-o B u g SPC i n SPC d e r SPC C-n C-a C-p C-p C-k 
C-y C-n C-n C-n C-n C-n C-n C-n C-y C-p C-p C-p C-p 
C-p C-p D o k u m e n t a t i o n SPC v o n C-x o <escape> 
< C-x o SPC o p e n - n e t w o r k - s t r e a m : 
C-n C-n C-n C-p C-p C-a C-o " C-d C-n C-n C-n C-n C-e 
" <return> C-p C-p C-k C-k C-k C-y <return> - SPC ' 
u n l e s s SPC y o u SPC s p e c i f y SPC a n SPC 
o u t p u t SPC s t r e a m . . . " <backspace> <backspace> 
<backspace> <backspace> SPC o f <backspace> r SPC f 
i l t e r SPC f u n c t i o n " <backspace> ' <return> 
SPC SPC n o t SPC p o s s i b l e SPC w i t h SPC t 
h i s SPC C-x C-s M-x a p r <tab> <return> b u g <return> 
C-x o C-s r e p C-s C-s C-s C-s C-a C-x o M-x r e p 
o r t - e m <tab> <return>

Recent messages:
Quit
Type C-x 4 C-o RET to restore the other window, C-M-v to scroll help.
Mark set
Quit
Mark set [4 times]
Auto-saving...done
Mark set [2 times]
Saving file /home/jr/share/projects/simacs/elisp/new_emacs_commands.txt...
Wrote /home/jr/share/projects/simacs/elisp/new_emacs_commands.txt
Mark saved where search started