bug#19591: 24.4; file & buffer compare failures

[Glenn Linderman]

I'm delighted that emacs 24.4 can now open all files, even those
that have characters in their names that are not part of the current
ANSI set.

However, the auxiliary program diff when launched by emacs still doesn't
accept files with such characters. The latest version of diff for
windows that I can find is 2.8.7. The error message from diff in the
error buffer seems to contain the proper characters for the file name,
but diff reports it cannot find the file so I tihnk it is a deficiency
in diff, like was in emacs versions prior to 24.4, using the
"bytes" version of open instead of the "widechars" version.

While it may be somewhat inefficient, it would be possible for emacs to
work around the deficiency of diff by saving temporary copies of the
buffers to be compared using generated names in the ANSI subset.

Obviously I can achieve that myself, and have a number of times, but then
one must be careful to copy the fixed data back to the original file.


In GNU Emacs 24.4.1 (x86_64-w64-mingw32)
 of 2014-10-20 on KAEL
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/z/emacs --host=x86_64-w64-mingw32
 --target=x86_64-w64-mingw32 --build=x86_64-w64-mingw32 --with-wide-int
 --with-jpeg --with-xpm --with-png --with-tiff --with-rsvg --with-xml2
 --with-gnutls --with-xft --with-sound=yes --with-file-notification=yes
 --without-dbus --without-imagemagick 'CFLAGS=-Ofast
 -fomit-frame-pointer -funroll-loops -g0 -pipe' 'CPPFLAGS=-DNDEBUG
 -DDBUS_STATIC_BUILD' 'LDFLAGS=-static-libgcc -static-libstdc++ -static
 -s -Wl,-s''

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1252

Major mode: Emacs-Lisp

Minor modes in effect:
  shell-dirtrack-mode: t
  which-function-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<backspace> <backspace> o <backspace> <backspace> o
p e n s SPC o n e SPC t h a t SPC i t SPC p <backspace>
<backspace> <return> p r e v i o u s l y SPC c o u
l d n ' <backspace> ' t SPC ( b e c a u s e SPC t h
e SPC c h a a r <backspace> <backspace> r a c e <backspace>
t e r SPC i s SPC n o t SPC i n SPC t h e SPC c u r
r e n t A N S I <backspace> <backspace> <backspace>
<backspace> SPC A N S I <return> s e t ) , SPC t h
e SPC d i s p l a y SPC o f SPC t h e SPC f i l e SPC
n a m e SPC i n SPC t h e SPC t i t l e SPC b a r SPC
h a s SPC c h o s e <backspace> <backspace> <backspace>
<backspace> <backspace> s u c h SPC c h a r a c t e
r s <return> o m i t t e d . <help-echo> <down-mouse-1>
<mouse-1> C-n C-SPC 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-b C-b C-b C-b C-b
<escape> w <help-echo> <down-mouse-1> <mouse-1> C-SPC
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-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 <escape> w <help-echo> <down-mouse-1>
<mouse-1> C-SPC <escape> > <escape> w <down-mouse-1>
<mouse-1> <escape> < <help-echo> <down-mouse-1> <mouse-1>
C-x k <return> y e s <return> <escape> x r e p o r
t <tab> <return>

Recent messages:
Checking 151 files in d:/emacs/share/emacs/24.4/lisp/emacs-lisp...
Checking 24 files in d:/emacs/share/emacs/24.4/lisp/cedet...
Checking 57 files in d:/emacs/share/emacs/24.4/lisp/calendar...
Checking 87 files in d:/emacs/share/emacs/24.4/lisp/calc...
Checking 95 files in d:/emacs/share/emacs/24.4/lisp/obsolete...
Checking for load-path shadows...done
Auto-saving...done
Mark set [3 times]
Saved text from "
I'm delighted that emacs 24.4 can, at l"

Load-path shadows:
None found.

Features:
(pp shadow sort gnus-util mail-extr emacsbug message format-spec rfc822
mml mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils add-log python-mode derived skeleton advice
help-fns edmacro kmacro cl-macs thingatpt flymake rx shell pcomplete
cc-cmds cc-engine cc-vars cc-defs compile cl gv cl-loaddefs cl-lib
comint ansi-color ring misearch multi-isearch help-mode easymenu
whitespace which-func imenu time-date tooltip electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp
w32-common-fns disp-table w32-win w32-vars tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment lisp-mode prog-mode register
page menu-bar rfn-eshadow timer select scroll-bar 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 minibuffer nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process w32notify w32
multi-tty emacs)

Memory information:
((conses 16 169994 18131)
 (symbols 56 23492 0)
 (miscs 48 92 169)
 (strings 32 28274 6229)
 (string-bytes 1 978775)
 (vectors 16 21772)
 (vector-slots 8 1297449 203189)
 (floats 8 77 457)
 (intervals 56 1134 37)
 (buffers 960 17))