From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
Subject: bug#27563: [PATCH v3 0/2] Make ghostscript reproducible.
Date: Sat, 08 Jul 2017 16:32:02 +0200
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To: Danny Milosavljevic <dannym@scratchpost.org>
Cc: 27563@debbugs.gnu.org

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> On Fri, 07 Jul 2017 19:51:10 +0200
> ludo@gnu.org (Ludovic Court=C3=A8s) wrote:
>
>> For CreationDate/ModDate, I think it should honor SOURCE_DATE_EPOCH as
>> in
>> <https://anonscm.debian.org/git/printing/ghostscript.git/tree/debian/pat=
ches/2010_add_build_timestamp_setting.patch?id=3De2bf3ad7026afe13636d493743=
0c3fdae7854078>.
>
> Really?  I've been leaving them off, too.  Especially because of this fun=
ny comment in the upstream ghostscript:
>
> /* Initialize the IDs allocated at startup. */
> void
> pdf_initialize_ids(gx_device_pdf * pdev)
> {
> ...
>     /*
>      * Acrobat Distiller sets CreationDate and ModDate to the current
>      * date and time, rather than (for example) %%CreationDate from the
>      * PostScript file.  We think this is wrong, but we do the same.
>      */
>     {
> ... proceed to set CreationDate and ModDate to the current time.
>     }
> }

I guess they hamper reproducibility if they=E2=80=99re always created?  In =
that
case, they need to follow SOURCE_DATE_EPOCH; if OTOH they=E2=80=99re only
created in specific cases that don=E2=80=99t matter much, we can leave them.

>> For the two UUIDs (and =E2=80=9CID=E2=80=9D too?), maybe we can use, say,
>> GS_GENERATE_UUIDS; if set to 0 or =E2=80=9Cno=E2=80=9D it=E2=80=99s disa=
ble, otherwise it=E2=80=99s
>> enabled.
>
> That would look like this:
>
> if (!getenv("GS_GENERATE_UUIDS") || strcmp(getenv("GS_GENERATE_UUIDS"), "=
0") =3D=3D 0 || strcmp(getenv("GS_GENERATE_UUIDS"), "no") =3D=3D 0) ...

Yes.

Thanks!

Ludo=E2=80=99.