bug#4527: Emacs removes Extended Attributes when saving

bug#4527: Emacs removes Extended Attributes when saving

[David Euresti]

When I edit a file that contains xattrs the xattrs are removed when I
save the file inside of emacs.

Example:
$ touch a.txt
$ xattr a.txt user.foo bar
$ xattr -l a.txt
user.foo: bar
$ emacs a.txt
add a line C-x C-s
$ xattr -l a.txt

You can get the xattr tool from
http://pypi.python.org/packages/source/x/xattr/xattr-0.4.tar.gz

Thanks,
David

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/share/emacs/22.2/etc/DEBUG for instructions.


In GNU Emacs 22.2.1 (x86_64-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2008-09-05 on yellow, modified by Ubuntu
Windowing system distributor `The X.Org Foundation', version 11.0.10600000
configured using `configure  '--build=x86_64-linux-gnu'
'--host=x86_64-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib'
'--libexecdir=/usr/lib' '--localstatedir=/var'
'--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes'
'--enable-locallisppath=/etc/emacs22:/etc/emacs:/usr/local/share/emacs/22.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/22.2/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/22.2/leim'
'--with-x=yes' '--with-x-toolkit=athena' '--with-toolkit-scroll-bars'
'build_alias=x86_64-linux-gnu' 'host_alias=x86_64-linux-gnu'
'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g
-Wl,--as-needed' 'CPPFLAGS=''

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
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  which-function-mode: t
  delete-selection-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
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<backspace> <backspace> <backspace> <backspace> / b
i n <tab> <tab> <tab> <backspace> <backspace> <backspace>
<backspace> <backspace> C-g <help-echo> <help-echo>
C-x 3 <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <up> <up> <up> <up>
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
<up> <up> <down> <up> <left> <help-echo> <help-echo>
<help-echo> <help-echo> C-x C-f ~ / p r o <tab> b e
<tab> U <tab> t <backspace> <backspace> u t <tab> <tab>
<backspace> <backspace> <tab> <tab> b e a <tab> <tab>
<tab> / <tab> u t <tab> <backspace> <backspace> U t
<tab> <tab> <tab> E <tab> x <tab> t <tab> <backspace>
<backspace> t e n d <tab> <return> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> <down> <down> <down>
<down> <down> <down> <down> <prior> <prior> <prior>
<prior> <down> <down> <down> <next> <next> <next> <next>
<prior> <prior> <prior> <prior> M-x r e p o <tab> r
t <tab> <return>

Recent messages:
Making completion list...
Loading help-mode...done
Making completion list... [4 times]
call-interactively: Beginning of buffer [2 times]
call-interactively: End of buffer [2 times]
call-interactively: Beginning of buffer
Making completion list...
Loading emacsbug...
Loading regexp-opt...done
Loading emacsbug...done

bug#4527: Emacs removes Extended Attributes when saving

[Stefan Monnier]

> When I edit a file that contains xattrs the xattrs are removed when I
> save the file inside of emacs.

You have to set backup-by-copying, otherwise the saved file is a new
file (with a new inode).  Of course, this also affects whether or not
hardlinks get broken when saving a file, which may be what you want or
may be what you don't want.


        Stefan