23.0.60; Non-ascii character string weirdness in Emacs Lisp mode

[Stephen Berman]

Some change after 2008-05-29 has resulted in strange behavior of
non-ascii characters in string in Emacs Lisp mode.  I have an elisp file
that contains the string "§" (that's the section charater, unicode
U+00A7).  When I visit that file in my Emacs builds from yesterday or
today, that character appears as "§" (backslash 247).  C-u C-x = says
this:

        character: § (4194215, #o17777647, #x3fffa7)
preferred charset: eight-bit (Raw bytes 0-255)
       code point: 0xA7
           syntax: w    which means: word
      buffer code: #xA7
        file code: not encodable by coding system utf-8-unix
          display: no font available

Yet I can type "§" (the section character) in Emacs Lisp mode in these
builds and it appears as it should and describe-character recognizes it.

Then, in my build from 2008-05-29, which does not have the above
problem, I wrote an elisp file containing the following string:

"§ßäöüµ" 
(in words: section German-eszet a-umlaut o-umlaut u-umlaut mu)

When I visit that file in my builds from yesterday or todo I see this:

"§ßäöüµ"
(in words: A-with-circumflex section A-with-tilde \237 A-with-tilde
currency-character A-with-tilde pilcrow A-with-tilde one-over-four
A-with-circumflex mu)

When I change this file (but not the string) and resave it in my
2008-05-29 build, and then in the newer builds invoke revert-buffer on
that already visited file, the string changes to the same as in the
earlier build, i.e., the characters now look like they should.  If, in
these newer builds, I now kill the buffer and then revisit the file, the
string no longer looks strange, but the same as in the earlier build.

I am using the Xft font backend and start Emacs with -fn "Dejavu Sans
Mono-10".



In GNU Emacs 23.0.60.1 (i686-pc-linux-gnu, GTK+ Version 2.12.0)
 of 2008-06-05 on escher
Windowing system distributor `The X.Org Foundation', version 11.0.70200000
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: @im=local
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Emacs-Lisp

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
  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
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
C-x C-f ~ / . e m a <tab> . d <tab> . t o <tab> d <tab> 
<return> y C-x k <return> C-x C-f <up> <M-backspace> 
m o <tab> <M-backspace> <M-backspace> <backspace> s 
i <tab> t o d <tab> o <tab> <return> C-s t C-w - p 
C-w C-s C-s C-s C-s C-s <down> C-x C-f <M-backspace> 
<M-backspace> d i a <tab> d i <tab> - l o n g <backspace> 
<backspace> g <return> C-x k <return> C-x C-f <up> 
<backspace> <tab> g b <tab> <return> C-s $ C-g C-s 
§ C-g C-g <help-echo> C-x C-f <M-backspace> t e s <tab> 
c h <tab> <return> C-x C-f t e s t <tab> . <tab> <tab> 
e <tab> <return> <down> <right> C-x k <return> C-x 
k <return> C-x k <return> C-x C-f <up> <up> <return> 
C-x C-f <up> <up> <return> <help-echo> <help-echo> 
<help-echo> <help-echo> M-x r e p o r <tab> <retur
n>