bug#13298: 24.3.50; Cannot write backup file; backing up in ~\.emacs.d\%backup%~

[Dmitry Gutov]

On 29.12.2012 16:06, Eli Zaretskii wrote:
> > Date: Sat, 29 Dec 2012 15:25:54 +0400
> > From: Dmitry Gutov <dgutov@yandex.ru>
> > CC: 13298@debbugs.gnu.org
> >
> > > > 1. emacs -Q
> > > > 2. M-x ido-mode OR M-x recentf-mode (either one's fine)
> > > > 3. C-x C-c
> > > > 4. See the message above and a new directory in ~\.emacs.d\ (if it
> > > > didn't exist already).
> > >
> > > Do you see a similar message when you edit a file and save it?
> >
> > I don't (tried with non-vc-controlled files, to be sure).
> >
> > But I see it when I quit gnus, by the way. Twice.
>
> Can you step with a debugger (e.g., Edebug) through
> backup-buffer-copy, and see why it errors out?  My crystal ball says
> it happens because of set-file-extended-attributes, in which case
> please tell what is the value of extended-attributes argument passed
> to backup-buffer-copy.

Indeed, it happens after a call to set-file-acl.

((acl . 
"O:BAG:S-1-5-21-909999172-181315677-756075521-513D:(A;;FA;;;SY)(A;;FA;;;BA)(A;;FA;;;S-1-5-21-909999172-181315677-756075521-1000)") 
(selinux-context nil nil nil nil))

> Also, do you see any other error messages in *Messages* when this
> happens?

Nope. Looks like this:

Saving file c:/Users/gutov/.newsrc...
Cannot write backup file; backing up in ~\.emacs.d\%backup%~
Wrote c:/Users/gutov/.newsrc
Saving c:/Users/gutov/.newsrc.eld...
Saving file c:/Users/gutov/.newsrc.eld...
Cannot write backup file; backing up in ~\.emacs.d\%backup%~
Wrote c:/Users/gutov/.newsrc.eld
Saving c:/Users/gutov/.newsrc.eld...done