From: ludo@gnu.org (Ludovic Courtès)
To: Danny Milosavljevic <dannym@scratchpost.org>
Cc: 27265@debbugs.gnu.org
Subject: bug#27265: [PATCH] file-systems: Use creation time if modification time is unset for ISO9660.
Date: Wed, 07 Jun 2017 01:19:34 +0200 [thread overview]
Message-ID: <87o9u066wp.fsf@gnu.org> (raw)
In-Reply-To: <20170606085037.28353-1-dannym@scratchpost.org> (Danny Milosavljevic's message of "Tue, 6 Jun 2017 10:50:37 +0200")
Danny Milosavljevic <dannym@scratchpost.org> skribis:
> * gnu/build/file-systems.scm (iso9660-superblock-uuid): Modify.
> ---
> gnu/build/file-systems.scm | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm
> index 10be0dc83..7737de3d0 100644
> --- a/gnu/build/file-systems.scm
> +++ b/gnu/build/file-systems.scm
> @@ -268,12 +268,18 @@ as a bytevector, or #f if DEVICE does not contain an iso9660 file system."
>
> (define (iso9660-superblock-uuid sblock)
> "Return the modification time of an iso9660 primary volume descriptor
> -SBLOCK as a bytevector."
> +SBLOCK as a bytevector. If that's not set, returns the creation time."
> ;; Drops GMT offset for compatibility with Grub, blkid and /dev/disk/by-uuid.
> ;; Compare Grub: "2014-12-02-19-30-23-00".
> ;; Compare blkid result: "2014-12-02-19-30-23-00".
> ;; Compare /dev/disk/by-uuid entry: "2014-12-02-19-30-23-00".
> - (sub-bytevector sblock 830 16))
> + (let* ((creation-time (sub-bytevector sblock 813 17))
> + (modification-time (sub-bytevector sblock 830 17))
> + (unset-time (make-bytevector 17 0))
> + (time (if (bytevector=? unset-time modification-time)
> + creation-time
> + modification-time)))
> + (sub-bytevector time 0 16))) ; strips GMT offset.
LGTM.
I suppose this makes those UUIDs a bit more unique, right?
Thank you,
Ludo’.
next prev parent reply other threads:[~2017-06-06 23:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-06 8:50 bug#27265: [PATCH] file-systems: Use creation time if modification time is unset for ISO9660 Danny Milosavljevic
2017-06-06 23:19 ` Ludovic Courtès [this message]
2017-06-07 6:35 ` Danny Milosavljevic
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