Subject: 24.0.50; scrolling problem with global-hl-line-mode: point fails to advance

From: David Reitter <[email-masked]>
Date: Tue, 25 May 2010 16:34:19 -0400

X-Debbugs-CC: [email-masked]

Emacs -Q
M-x about-emacs
M-: (set-frame-parameter nil 'height 25)
[important: this sets the frame so that the line "GNU and Freedom" is half-visible.\
M-x global-hl-line-mode

press <down> repeatedly, until we're on the "GNU and Freedom" line.  The line "Absence of Warranty" should now be visible at the bottom of the window.

Now press <down> once more.  This will NOT advance the cursor, but scroll the buffer up by just a pixel or two.
I am attaching two screenshots showing before and after.

I would expect it to scroll a full line and actually advance my point.

The recipe above applies to Emacs 24, but I can see it with a 23 branch build, too.

Interestingly, this does not reproduce when using `hl-line-mode' instead of `global-hl-line-mode', but I also don't see line-by-line scrolling then.

This problem may or may not be the same as bug#6264.  One difference in this report is 
that the point actually does not move here, while in #6264 the point still seems to move.  But that may just be a matter of setup.

Konrad Podczeck <[email-masked]>  contributed to this bug report.

In GNU Emacs 24.0.50.2 (x86_64-apple-darwin10.3.0, NS apple-appkit-1038.29)
 of 2010-05-05 on scarlett.local
Windowing system distributor `Apple', version 10.3.1038
configured using `configure  '--with-ns''

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

Major mode: Fundamental

Minor modes in effect:
  global-hl-line-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
x g l o b a l - h l <tab> <return> <up> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <down> <down> <down> <down> 
<down> <down> <down> <down> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <down> <help-echo> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <down> <down> <help-echo> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<escape> : <up> <right> <kp-delete> <kp-delete> <C-backspace> 
<C-backspace> <C-backspace> C-k C-k ( f r a m e - p 
a r a m e t e r SPC n i l SPC ' h e i g h t ) <return> 
<help-echo> <down-mouse-1> <mouse-1> <help-echo> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <help-echo> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<help-echo> <help-echo> <help-echo> <down> <help-echo> 
<help-echo> <down-mouse-1> <mouse-1> <help-echo> <help-echo> 
<menu-bar> <help-menu> <send-emacs-bug-report>

Recent messages:
Unable to load color "darkblue"
nil
Global-Hl-Line mode enabled
Unable to load color "darkblue" [2 times]
byte-code: End of buffer [5 times]
byte-code: Beginning of buffer [44 times]
call-interactively: Text is read-only
byte-code: Text is read-only: #<buffer  *Minibuf-1*> [2 times]
25 (#o31, #x19)
byte-code: Beginning of buffer [18 times]
byte-code: Beginning of buffer

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr message rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mailabbrev mail-utils gmm-utils mailheader emacsbug
cus-start cus-load hl-line tooltip ediff-hook vc-hooks lisp-float-type
mwheel ns-win easymenu tool-bar dnd fontset image fringe lisp-mode
register page menu-bar rfn-eshadow timer select scroll-bar mldrag mouse
jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
loaddefs button minibuffer faces cus-face files text-properties overlay
md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process ns multi-tty
emacs)

===
ALSO IN:

In GNU Emacs 23.2.50.1 (x86_64-apple-darwin10.3.1, NS apple-appkit-1038.29)
 of 2010-05-10 on elin.psy.cmu.edu
Windowing system distributor `Apple', version 10.3.1038
configured using `configure  '--with-ns''

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
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  global-hl-line-mode: t
  which-function-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> <help-echo> <down-mouse-1> <help-echo> 
<mouse-1> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <down-mouse-1> <mouse-1> <help-echo> <help-echo> 
<escape> x § g l o b a l - <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> g l o b a l - h l <tab> <return> <down> 
<down> <down> <down> <down> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <down> <down> <down> <down> <down> <down> 
<down> <down> <help-echo> <wheel-up> <double-wheel-up> 
<triple-wheel-up> <triple-wheel-up> <triple-wheel-up> 
<triple-wheel-up> <triple-wheel-up> <triple-wheel-up> 
<triple-wheel-up> <triple-wheel-up> <triple-wheel-up> 
<triple-wheel-up> <triple-wheel-up> <triple-wheel-up> 
<triple-wheel-up> <triple-wheel-up> <triple-wheel-up> 
<triple-wheel-up> <triple-wheel-up> <wheel-up> <help-echo> 
<down-mouse-1> <mouse-1> <help-echo> <escape> : ( f 
r a m e - p a r a m e t e r s SPC n i l SPC ' h e i 
g h t ) <return> q <escape> : <up> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <down-mouse-1> 
<mouse-1> <backspace> <return> <up> <up> <help-echo> 
<help-echo> <help-echo> <menu-bar> <help-menu> <se
nd-emacs-bug-report>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Unable to load color "darkblue"
Global-Hl-Line mode enabled
Unable to load color "darkblue"
byte-code: Beginning of buffer [20 times]
Entering debugger...
Back to top level.
22 (#o26, #x16)

Load-path shadows:
None found.

Features:
(shadow sort mail-extr message ecomplete rfc822 mml mml-sec
password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
time-date mm-util mail-prsvr gmm-utils wid-edit mailheader canlock sha1
hex-util hashcash mail-utils emacsbug help-mode view debug cus-start
cus-load hl-line easy-mmode which-func imenu tooltip ediff-hook vc-hooks
lisp-float-type mwheel ns-win easymenu tool-bar dnd fontset image fringe
lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar
mldrag mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev loaddefs button minibuffer faces cus-face files text-properties
overlay md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process ns multi-tty
emacs)