bug#22795: 25.0.91; Can't write read only file on w32

[Ota, Takaaki]

Sorry, I haven't made much progress.  I confirmed that it was
reproducible with the latest 25.0.94.  Let me resume looking into it
and I will send you further facts and questions.

-Tak

Sat, 14 May 2016 12:17:03 +0300: Eli Zaretskii <eliz@gnu.org> wrote:

> > Date: Tue, 01 Mar 2016 18:27:35 +0200
> > From: Eli Zaretskii <eliz@gnu.org>
> > Cc: 22795@debbugs.gnu.org
> > 
> > > Date: Mon, 29 Feb 2016 13:34:36 -0800
> > > CC: <22795@debbugs.gnu.org>
> > > From: "Ota, Takaaki" <Takaaki.Ota@am.sony.com>
> > > 
> > > I just tried again with "run -Q" from gdb and the result is the same.
> > > 24.5 never called sys_rename() and 25.0.91 called sys_rename() with
> > > two same names.
> > 
> > What about Frename_file? does 24.5 call it in this scenario?
> > 
> > If it doesn't, then please look at the beginning of backup-buffer (in
> > files.el), make sure it is called in 24.5 in this scenario, and then
> > please tell what are the values of real-file-name and backup-info in
> > this part at the beginning of backup-buffer:
> > 
> >     (let* ((real-file-name (file-chase-links buffer-file-name))
> >            (backup-info (find-backup-file-name real-file-name)))
> > 
> > Also, what are the values of make-backup-files, backup-inhibited, and
> > buffer-backed-up in the buffer that visits the read-only file?
> > 
> > Btw, is that file under some kind of version control, per chance?
> > 
> > And please make sure, from now on, to test everything in "emacs -Q",
> > to prevent any customizations from getting in the way of this
> > investigation.
> 
> Ping!  Can we please continue this investigation?
> 
> If the problem is no longer reproducible with the latest pretest
> 25.0.9x, or if you can no longer afford looking into this, I will most
> probably close the bug.
> 
> Thanks.
>