Regression: C-n doesn't move point when selective-display enabled

[Eric Hanchrow]

I originally posted this bug in February (see
http://lists.gnu.org/archive/html/emacs-pretest-bug/2004-02/msg00237.html);
I can't remember if the problem was fixed afterwards, but it's
certainly present now.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

Place the following in a file named `/tmp/x'
======cut here=====
Barf

        Whee!

Yadda
======cut here=====

(the above contains three lines, no tabs, and no trailing spaces, for
a total of 27 characters)

Now do the following:

* start `emacs -q --no-site-file'

* find the file: C-x C-f /tmp/x RET

* turn on selective-display: C-u C-x $

* attempt to move point forward: C-n C-n

Note that the cursor did not appear to move after the second C-n.
That's the bug; it should have appeared on the third visible line
(right before the `Y').

* sanity check: C-x =

You should see point 6 of 27.

* again attempt to move point forward: C-n

* again sanity check: C-x =

It's still at 6 of 27.

If it matters, you can "un-stick" point by typing C-f, *then* typing
C-n; in that case, point indeed winds up on the third visible line,
where I'd expect it to.

In GNU Emacs 21.3.50.3 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2005-01-16 on debian
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: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Major mode: Nroff

Minor modes in effect:
  erc-autojoin-mode: t
  erc-button-mode: t
  erc-ring-mode: t
  erc-pcomplete-mode: t
  erc-track-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-netsplit-mode: t
  erc-irccontrols-mode: t
  erc-noncommands-mode: t
  desktop-save-mode: t
  mouse-wheel-mode: t
  display-time-mode: t
  auto-compression-mode: t
  iswitchb-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  line-number-mode: t

Recent input:
2 C-x C-f / t m p / x RET ESC : ESC ( e r a s e - b 
u f f e r RET C-x o C-n C-n C-@ C-n C-n C-n C-n C-n 
ESC w C-x o C-y C-x C-s C-x = C-x - ESC C-v C-u C-x 
$ ESC < C-n C-n C-n C-n C-x = C-n C-n C-x = ESC C-v 
C-f C-n C-x o ESC v ESC C-r ^ T o : C-a C-x 1 ESC 0 
C-l C-l ESC x C-g ESC x r e p o r TAB b TAB RET

Recent messages:
nil
Mark set [2 times]
Wrote /tmp/x
point=28 of 27 (100%) column 0 
selective-display set to 4.
Mark set
Char: C-j (012, 10, 0xa) point=6 of 27 (19%) column 0  [2 times]
Mark saved where search started
Quit
Loading emacsbug...done

-- 
A novice of the temple once approached the Master Programmer with a question.
"Master, does Emacs have the Buddha nature?" the novice asked.
The Master Programmer had been in the temple for many years and
could be relied upon to know these things.  He thought for
several minutes before replying.  "I don't see why not.  It's
bloody well got everything else."