bug#12398: 23.4; Disabling fringes causes term to garble certain text output.

bug#12398: 23.4; Disabling fringes causes term to garble certain text output.

[Robert Park]

Steps to reproduce:

1. Disable fringes using Custom, such that this appears in the
custom-set-variables:

    '(fringe-mode 0 nil (fringe))

2. Open a term buffer with `M-x term' (shell and ansi-term untested, sorry)

3. Run any program at all that will output a line that is longer
than the width of your terminal window. Good examples would be:

    $ echo `seq 100`

or

    $ cat some_file_with_long_lines.txt

Expected results:

The program runs and the output is displayed normally.

Actual results:

The program runs, but the output gets crammed all onto one line,
overlapping itself in a lossy way, and afterwards the prompt is lost and
any characters typed do not display. It is necessary to type C-l to
restore normal operation of the terminal.

Workaround:

Keeping the fringe only on the right-hand side seems to not trigger
this, eg, with this line in the .emacs:

    (set-fringe-mode (cons 0 1))

Potentially relevant details:

Working in a *very* large frame, that has been split both horizontally
and vertically multiple times, resulting in $COLUMNS=100 for the
terminal.

In GNU Emacs 23.4.1 (x86_64-pc-linux-gnu, GTK+ Version 2.24.10)
 of 2012-07-10 on komainu, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11300000
configured using `configure  '--build' 'x86_64-linux-gnu' '--build'
'x86_64-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/23.4/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.4/site-lisp:/usr/share/emacs/site-lisp'
'--with-crt-dir=/usr/lib/x86_64-linux-gnu' '--with-x=yes'
'--with-x-toolkit=gtk' '--with-toolkit-scroll-bars'
'build_alias=x86_64-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector
--param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall
-DDEBIAN -O2' 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

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: en_CA.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: terminal

Minor modes in effect:
  shell-dirtrack-mode: t
  show-paren-mode: t
  global-whitespace-mode: t
  global-linum-mode: t
  linum-mode: t
  global-hl-line-mode: t
  tabbar-mwheel-mode: t
  tabbar-mode: t
  global-auto-revert-mode: t
  desktop-save-mode: t
  cua-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
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  transient-mark-mode: t

Load-path shadows:
/usr/share/emacs/23.4/site-lisp/debian-startup hides
/usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/23.4/site-lisp/cmake-data/cmake-mode hides
/usr/share/emacs/site-lisp/cmake-mode
/usr/share/emacs23/site-lisp/dictionaries-common/ispell hides
/usr/share/emacs/23.4/lisp/textmodes/ispell
/usr/share/emacs23/site-lisp/dictionaries-common/flyspell hides
/usr/share/emacs/23.4/lisp/textmodes/flyspell

Features:
(shadow sort mail-extr message sendmail 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 mailheader canlock sha1 hex-util
hashcash mail-utils emacsbug help-mode view noutline outline python-mode
imenu flymake rx shell cc-cmds cc-engine cc-vars cc-defs regexp-opt
vc-git uniquify paren cus-start cus-load server ace-jump-mode winner
sr-speedbar speedbar sb-image ezimage dframe assoc setup-private
setup-whitespace disp-table whitespace robru-style linum hl-line tabbar
info color-theme easymenu wid-edit cl cl-19 term-love dirtrack
ansi-color shell-pop backups autorevert bigscreen modern advice help-fns
advice-preload desktop edmacro kmacro cua-base compile comint ring
emacs-goodies-el emacs-goodies-custom emacs-goodies-loaddefs easy-mmode
devhelp tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
font-setting 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 dbusbind system-font-setting
font-render-setting gtk x-toolkit x multi-tty emacs)


-- 
http://gottengeography.ca

bug#12398: 23.4; Disabling fringes causes term to garble certain text output.

[Chong Yidong]

Robert Park <robru@gottengeography.ca> writes:

> 1. Disable fringes using Custom, such that this appears in the
> custom-set-variables:
>
>     '(fringe-mode 0 nil (fringe))
>
> 2. Open a term buffer with `M-x term' (shell and ansi-term untested, sorry)
>
> 3. Run any program at all that will output a line that is longer
> than the width of your terminal window.
>
>     $ echo `seq 100`
>
> The program runs, but the output gets crammed all onto one line

Thanks for the bug report.  This bug has been fixed in Emacs 24.

bug#12398: 23.4; Disabling fringes causes term to garble certain text output.

[Robert Park]

On Sat, Oct 13, 2012 at 4:00 AM, Chong Yidong <cyd@gnu.org> wrote:
> Thanks for the bug report.  This bug has been fixed in Emacs 24.

Was it only *just* fixed? Because I can still reproduce it in Emacs 24.1.1.

1. eval this elisp:

(set-fringe-mode (cons 0 0))

2. Run any command that outputs long lines in term-mode:

$ echo `seq 100`

Expected output:

robru ~
$ echo `seq 100`
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
27 28 29 30 31 32
33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
56 57 58 59 60 61
62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100

Actual output:

$ bru ~4 95 96 97 98 99 100 72 73 74 75 76 77 78 79 80 81 82 83 84 85
86 87 88 89 90 91

Note that I have a two-line $PS1 set, and the output appears to be the
second line of my prompt ('$ ') laid over the first line of my prompt
('robru ~') laid over the third line of the output (the numbers).

Further, once this condition is triggered, *all* further output
regardless of line length just overwrites this same one line, until
C-l is typed, then everything goes back to normal (at least until
another long line is printed).

The workaround is to enable the fringe on just one side:

(set-fringe-mode (cons 0 1))

And then everything works fine.

-- 
http://gottengeography.ca

bug#12398: 23.4; Disabling fringes causes term to garble certain text output.

[Chong Yidong]

Robert Park <robru@gottengeography.ca> writes:

>> Thanks for the bug report.  This bug has been fixed in Emacs 24.
>
> Was it only *just* fixed? Because I can still reproduce it in Emacs
> 24.1.1.

It is fixed in trunk, so the fix will be in 24.3.