--- Begin Message ---
Subject: |
[PATCH] file-systems: Use creation time if modification time is unset for ISO9660. |
Date: |
Tue, 6 Jun 2017 10:50:37 +0200 |
* 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.
(define (iso9660-uuid->string uuid)
"Given an UUID bytevector, return its timestamp string."
--- End Message ---
--- Begin Message ---
Subject: |
Re: bug#27265: [PATCH] file-systems: Use creation time if modification time is unset for ISO9660. |
Date: |
Wed, 7 Jun 2017 08:35:34 +0200 |
Hi Ludo,
On Wed, 07 Jun 2017 01:19:34 +0200
address@hidden (Ludovic Courtès) wrote:
> LGTM.
>
> I suppose this makes those UUIDs a bit more unique, right?
Yes, and it also aligns with what util-linux libblkid is doing (the same; see
probe_iso9660 in util-linux-2.29.2/libblkid/src/superblocks/iso9660.c).
Pushed as c6aee77e297ee9c96412825127a921dbd1d10e92 to master.
--- End Message ---