From: Jens Schmidt via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 66546@debbugs.gnu.org
Subject: bug#66546: 30.0.50; save-buffer to write-protected file without backup fails
Date: Mon, 16 Oct 2023 22:04:15 +0200 [thread overview]
Message-ID: <87wmvmfi68.fsf@sappc2.fritz.box> (raw)
In-Reply-To: <838r82q0gi.fsf@gnu.org> (Eli Zaretskii's message of "Mon, 16 Oct 2023 14:19:09 +0300")
Eli Zaretskii <eliz@gnu.org> writes:
>> From: Jens Schmidt <jschmidt4gnu@vodafonemail.de>
>> Cc: 66546@debbugs.gnu.org
>> Date: Sun, 15 Oct 2023 20:59:42 +0200
>>
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>> > In that case, does the change below fix the original problem?
>>
>> It does, thanks.
>
> I've now installed that on the master branch.
Thanks. Now that's out of the way, should I then work on what I have
called issue B in the initial message and on ERT tests for both issues?
Or do you still think there is more discussion required on these
beforehand?
>> > + ;; If set-file-extended-attributes fails to make the
>> > + ;; file writable, fall back on set-file-modes.
>> > + (with-demoted-errors "Error setting attributes: %s"
>> > + (set-file-extended-attributes buffer-file-name
>> > + (nth 1 setmodes)))
>>
>> How exactly could above call to `set-file-extended-attributes' *succeed*
>> to make the file writable?
>
> I don't know, and I don't think we should care. Due to the
> above-mentioned system-dependencies, Emacs generally treats extended
> attributes as opaque objects, and only tries hard to preserve them
> where expected. So the above is our best effort to preserve the
> attributes, which is why we call set-file-modes only if absolutely
> necessary, since doing that in general affects the extended
> attributes.
That explains (partially) what I did not understand in your solution.
But still, to me it seems that the two forms
(setq setmodes
(list (file-modes buffer-file-name)
(with-demoted-errors
"Error getting extended attributes: %s"
(file-extended-attributes buffer-file-name))
buffer-file-name))
(with-demoted-errors "Error setting attributes: %s"
(set-file-extended-attributes buffer-file-name
(nth 1 setmodes)))
, if limiting them to the extended attribute calls and if ignoring outer
context, could be simplified to
(set-file-extended-attributes
buffer-file-name
(file-extended-attributes buffer-file-name))
(If not, why not?)
And wouldn't that be, in this context, just a no-op?
I fully understand that the extended attributes stored in `setmodes' are
required later to restore the attributes of the file after it has been
written to. And in that context I understand why we call
`set-file-extended-attributes'. But here not really, yet.
next prev parent reply other threads:[~2023-10-16 20:04 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-14 19:09 bug#66546: 30.0.50; save-buffer to write-protected file without backup fails Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-14 19:32 ` Eli Zaretskii
2023-10-14 20:31 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-15 5:33 ` Eli Zaretskii
2023-10-15 9:34 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-15 9:54 ` Eli Zaretskii
2023-10-15 11:39 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-15 12:12 ` Eli Zaretskii
2023-10-15 18:59 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-16 11:19 ` Eli Zaretskii
2023-10-16 20:04 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors [this message]
2023-10-17 10:48 ` Eli Zaretskii
2023-10-17 20:12 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-18 11:32 ` Eli Zaretskii
2023-10-18 20:36 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-19 4:40 ` Eli Zaretskii
2023-10-19 21:12 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-20 6:06 ` Eli Zaretskii
2023-10-21 17:56 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-21 19:02 ` Eli Zaretskii
2023-10-21 20:17 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-22 4:57 ` Eli Zaretskii
2023-10-22 9:45 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-25 12:58 ` Eli Zaretskii
2023-10-29 14:23 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-10-29 14:39 ` Eli Zaretskii
2023-11-01 19:06 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-11-02 6:47 ` Eli Zaretskii
2023-11-03 21:02 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-11-04 8:58 ` Eli Zaretskii
2023-11-04 12:30 ` Jens Schmidt via Bug reports for GNU Emacs, the Swiss army knife of text editors
2023-11-04 12:59 ` Eli Zaretskii
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