pos-visible-in-window-p at ellipsis

[David Reitter]

Start an emacs -Q , presumably in as non-TTY  (tested with the Carbon  
port)

M-x latex-mode
M-x outline-minor-mode

Enter the following text into the buffer

\section{heading}
this is a sentence.

M-x hide-subtree
You should now see this:

\section{heading}...

Place the point at the ellipsis (...) and enter

M-: (pos-visible-in-window-p (point) nil 'partial) RET

Now hit C-f to place the point right after the ellipsis, and enter

M-: (pos-visible-in-window-p (point) nil 'partial) RET


The bug is that both `pos-visible-in-window-p' returns the same pixel  
coordinates at both positions.  According to the doc, " X and Y are  
the pixel coordinates relative to the top left corner of the window.",  
and I presume this refers to the coordinates of whatever the point is  
on.

This is practically relevant because I'm using that function to  
position the point in just the right place (i.e. maintain horizontal  
pixel position) when a user goes up or down a line (and C-n etc  
doesn't do that.)



In GNU Emacs 22.1.50.1 (i386-apple-darwin9.1.0, Carbon Version 1.6.0)
 of 2007-12-21 on scarlett
Windowing system distributor `Apple Inc.', version 10.5.1
configured using `configure  '--without-x' '--prefix=/usr/local''

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: iso-8859-1
  default-enable-multibyte-characters: t

Major mode: LaTeX

Minor modes in effect:
  shell-dirtrack-mode: t
  outline-minor-mode: t
  encoded-kbd-mode: t
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: identity

Recent input:
<help-echo> <down-mouse-1> <mouse-1> <help-echo> <down-mouse-1>
<mouse-1> q M-a <up> C-k C-k C-k C-k C-k C-k <return>
<return> <return> t h i s SPC i s SPC a SPC <backspace>
n <backspace> <backspace> c o l l a p s e d SPC s e
n t e n c e <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> n o
t SPC a SPC s e n t e n c e . <up> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<S-right> <S-right> <left> <left> <escape> x o u t
l i <tab> e <tab> - m o <tab> <backspace> <backspace>
<backspace> i n <tab> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> m o d e <return> <help-echo>
<down-mouse-1> <mouse-1> <down-mouse-1> <mouse-movement>
<mouse-1> <double-down-mouse-1> <double-mouse-1> <help-echo>
<menu-bar> <hide> <hide-entry> <help-echo> <help-echo>
<help-echo> <down-mouse-1> <mouse-1> <up> <escape>
x l a t e x - m o d e <return> \ s e c i o n <backspace>
<backspace> <backspace> t i o n { h a d i n g <backspace>
<backspace> <backspace> <backspace> <backspace> e a
d i n g { <backspace> { <backspace> } <return> <help-echo>
<help-echo> <escape> x o u t l i n e - m i n o r -
m o d e <return> <help-echo> <menu-bar> <outline> <hide-subtree>
<right> <left> <escape> : M-v C-y <return> <right>
<escape> : C-y <return> <menu-bar> <help-menu> <se
nd-emacs-bug-report>

Recent messages:
Loading outline...done
outline-back-to-heading: before first heading
Loading tex-mode...
Loading regexp-opt...done
Loading tex-mode...done
Loading skeleton...done
Outline minor mode enabled
call-interactively: Beginning of buffer
(133 48) [2 times]
Loading emacsbug...done