bug#3745: 23.0.95; emacs-23.0.95: unibyte-display-via-language-environment

[Jay Berkenbilt <ejb@ql.org>]

I have this habit of editing binary files in emacs.  I notice a change
in behavior in 23.0.95 (which is the first 23 pretest I've run) relative
to what I've seen in emacs 22.  Specifically, I no longer see most
characters in unibyte mode.  I'll be specific.

xrdb -load /dev/null

emacs-22 -q
M-x set-variable unibyte-display-via-language-environment RET t RET
M-x set-language-environment RET Latin-1 RET
M-x find-file-literally RET /bin/ls RET

In this case, I see ^x for characters between 0 and \037, the ASCII
character for \040-\177, \ooo for (unprintable) characters between \200
and \237, and the ISO-Latin-1 character for \240 through \377, as
expected.

With the same commands under emacs-23.0.95, I see ^x for \0 to \037, and
I see some normal 7-bit ASCII characters, but for other ASCII characters
and for everything \200 or above, I see various rectangles of various
widths.  I can still see the buffer the way I want to by doing

C-x RET c iso-latin-1-unix RET C-x C-f /bin/ls

which is, I suppose, pretty much the same thing, but it seems like the
old behavior is right and the new behavior is probably a bug.  Please
let me know if there's any other information I should supply.

----------------------------------------------------------------------

In GNU Emacs 23.0.95.1 (i686-pc-linux-gnu, GTK+ Version 2.16.1)
 of 2009-06-25 on soup
Windowing system distributor `The X.Org Foundation', version 11.0.10402000
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_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  which-function-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
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t

Recent input:
C-h v s e t SPC l a n <tab> C-g C-h f s e t SPC a <backspace> 
l <tab> a n <tab> e n <tab> <return> C-x b <return> 
C-s s e t - l a n g C-s C-g C-g C-x 1 C-l C-v C-n C-n 
C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
C-n C-n C-n C-n C-n C-n C-z C-o C-n C-o C-o <tab> ( 
s e t - l a n g M-/ <backspace> SPC " L a t i n - 1 
" ) C-x C-e C-x C-s C-x b l s <tab> <return> C-x C-v 
<return> C-x b <return> C-x C-e C-x b <return> C-x 
C-v <return> C-x k <return> C-x C-f / b i n l <backspace> 
/ l s <tab> <return> M-x u n i <tab> b <tab> <return> 
C-v C-v C-v C-v C-v M-> M-< C-n C-x u C-x u C-f C-f 
C-z C-v C-f C-f C-f C-f C-f C-b C-z C-v C-x b <return> 
C-s s e t - l a n C-g C-g C-x C-f ~ / e l <tab> q f 
<tab> <M-backspace> <M-backspace> X r e <tab> f o n 
<tab> <return> C-n C-n C-n C-n C-n C-n C-n C-n C-n 
C-n C-n C-n C-n M-f M-f M-f C-f C-SPC C-e M-w C-x C-x 
M-w C-x C-f / b i n / l s <return> C-v C-v C-v C-v 
C-v C-v C-v C-v C-v C-x k <return> C-h f u n i <tab> 
b <tab> <return> C-x o C-e M-b <return> C-x m q <tab> 
C-g C-x k <return> y e s <return> M-x r e p o r t SPC 
e m SPC b SPC <return>

Recent messages:
U+0020
U+0028
Quit
Note: file is write protected
Mark set
Making completion list...
Type C-x 1 to delete the help window.
Note: file is write protected
Quit
Scanning for dabbrevs...100%

-- 
Jay Berkenbilt <ejb@ql.org>