buff-menu header wrong char

buff-menu header wrong char

[Robert J. Chassell]

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Today's GNU Emacs CVS snapshot, Thu, 2004 Dec  2  16:54 UTC
GNU Emacs 21.3.50.19 (i686-pc-linux-gnu, GTK+ Version 2.4.13) 
started with

     emacs/src/emacs -Q --eval '(setq Buffer-menu-use-header-line nil)'

A *Buffer List* looks like this:

    CRM Buffer                Size  Mode              File
    ôôô ôôôôôô                ôôôô  ôôôô              ôôôô
    .   *scratch*                0  Lisp Interaction
      * *Messages*             150  Fundamental

instead of like this:

    CRM Buffer                Size  Mode              File
    --- ------                ----  ----              ----
    .   *scratch*                0  Lisp Interaction
      * *Messages*             150  Fundamental

[i.e., the hyphens, ---, are replaced by the sequences of \364\364\364 ]

This comes from revision 1.75 to emacs/lisp/buff-menu.el of 2004/11/22
15:12:09, which includes a change to `list-buffers-noselect' that
tests

     (if (char-displayable-p ?—) ?— ?-)))

However, the documentation for `char-displayable-p' says

    On a multi-font display, the test is only whether there is an
    appropriate font from the selected frame's fontset to display
    char's charset in general.  Since fonts may be specified on a
    per-character basis, this may not be accurate.

When

    (let ((underline (if (char-displayable-p ?—) ?— ?-)))

is replaced by 

    (let ((underline  ?-))

the  *Buffer List* displays correctly.


Here is the info on   character: ô 

  character: ô (0364, 244, 0xf4)
    charset: eight-bit-graphic (8-bit graphic char (0xA0..0xFF))
 code point: 244
     syntax:   	which means: whitespace
buffer code: 0xF4
  file code: 0xF4 (encoded by coding system raw-text-unix)
    display: by this font (glyph code)
     -ETL-Fixed-Medium-R-Normal--16-160-72-72-C-80-ISO8859-1 (0xF4)



In GNU Emacs 21.3.50.19 (i686-pc-linux-gnu, GTK+ Version 2.4.13)
 of 2004-12-02 on benthic
Distributor `The XFree86 Project, Inc', version 11.0.40300001
configured using `configure '--with-type1' '--with-x-toolkit=gtk' '--with-pop' '--prefix=/usr/local' '--with-sound=yes''

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: nil
  default-enable-multibyte-characters: nil

Major mode: Lisp Interaction

Minor modes in effect:
  mouse-wheel-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  line-number-mode: t

Recent input:
d / u s r / . l o c M-b C-b C-d C-e a l / s r c / e 
m a c s <return> C-n C-n C-n C-n C-n C-b C-b C-b C-b 
C-b C-b C-SPC C-e C-b C-b C-b C-b C-b C-b C-b C-b C-b 
C-b C-b C-b C-b C-b C-b C-b C-SPC C-e M-w C-x b <return> 
C-n C-n <return> <return> C-y C-x o C-p C-u C-x = C-x 
h M-w C-x b <return> C-x o C-x o C-n C-n C-n C-n <return> 
<return> <return> C-y M-x r e <tab> p o r <tab> <r
eturn>

Recent messages:
Loading dired...done
Mark set [3 times]
Loading descr-text...done
Loading composite...done
Loading help-mode...done
Loading wid-edit...done
Char: ô (0364, 244, 0xf4) point=56 of 203 (27%) column 0 
Mark set [3 times]
Making completion list...
Loading emacsbug...done

-- 
    Robert J. Chassell                         
    bob@rattlesnake.com                         GnuPG Key ID: 004B4AC8
    http://www.rattlesnake.com                  http://www.teak.cc

Re: buff-menu header wrong char

[Stefan Monnier]

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> A *Buffer List* looks like this:
> 
>     CRM Buffer                Size  Mode              File
>     ôôô ôôôôôô                ôôôô  ôôôô              ôôôô
>     .   *scratch*                0  Lisp Interaction
>       * *Messages*             150  Fundamental

Hmm... my crystal ball tells me you're running in unibyte mode.
I'd *strongly* advise you don't do that.

>    (if (char-displayable-p ?—) ?— ?-)))

So it seems the problem is that in unibyte mode, char-displayable-p on the
non-ASCII char above returns non-nil (because you do have the font to
display such a char) even though the char will actually not be properly
displayed after it's inserted in the buffer because the insertion into the
unibyte buffer changes the char (I really think it should signal an error
instead, but that's another fight).

Does anyone object to the patch below?


        Stefan


--- mule-util.el	12 oct 2004 12:05:54 -0400	1.56
+++ mule-util.el	03 déc 2004 14:52:41 -0500	
@@ -2,7 +2,7 @@
 
 ;; Copyright (C) 1995 Electrotechnical Laboratory, JAPAN.
 ;; Licensed to the Free Software Foundation.
-;; Copyright (C) 2000, 2002 Free Software Foundation, Inc.
+;; Copyright (C) 2000, 2002, 2004  Free Software Foundation, Inc.
 
 ;; Keywords: mule, multilingual
 
@@ -356,6 +356,9 @@
   (cond ((< char 256)
 	 ;; Single byte characters are always displayable.
 	 t)
+	((not enable-multibyte-characters)
+	 ;; Maybe there's a font for it, but we can't put it in the buffer.
+	 nil)
 	((display-multi-font-p)
 	 ;; On a window system, a character is displayable if we have
 	 ;; a font for that character in the default face of the
@@ -377,5 +380,5 @@
 ;; coding: iso-2022-7bit
 ;; End:
 
-;;; arch-tag: 5bdb52b6-a3a5-4529-b7a0-37d01b0e570b
+;; arch-tag: 5bdb52b6-a3a5-4529-b7a0-37d01b0e570b
 ;;; mule-util.el ends here

Re: buff-menu header wrong char

[Kim F. Storm]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>
> Does anyone object to the patch below?

I cannot speak for anyone, but _I_ don't any problems with it.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk