bug#7052: next-line "cycling around"

[Philipp Müller]

To: bug-gnu-emacs@gnu.org
Subject: 23.1; next-line sometimes not working correctly
--text follows this line--

In certain files, the next-line command seems to work improperly. To be
more precise, if I scroll down to the last visible line in the
corresponding buffer and then do C-n (i.e. next-line), I would expect
the screen to scroll down some lines so I can see them (because the
point was at the bottom of visible part of the buffer). Instead, the
point jumps to the middle of the buffer and goes on from there. I.e. if
I hold down C-n to move the point some lines down, it may happen that
next-line kind of "cycles". I.e. the point walks down from the middle to
the bottom, jumps back to the middle, walks down, jumps back, walks
down, and so on. You can solve this problem easily by recentering (C-l),
but it would be nice to be able to scroll down just by holding C-n.
Unfortunately, this is a problem I encounter from time to time and I am
not able to reproduce. So I can't tell exactly, what the requirements
for the bug to appear are.


In GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.20.0)
 of 2010-03-29 on rothera, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.10706000
configured using `configure  '--build=i486-linux-gnu'
'--host=i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib'
'--libexecdir=/usr/lib' '--localstatedir=/var/lib'
'--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes'
'--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.1/leim'
'--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars'
'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu'
'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g' '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.utf8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  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
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e - <tab> b u <tab> <C-backspace> <C-backspace>
<kp-multiply> b u <tab> <backspace> u g <tab> <tab>
<home> r e p <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list... [3 times]
/usr/bin/mail is not an executable.  Setting mail-interactive to t.