# HG changeset patch
# User Bernhard M. Wiedemann <bwiedemann@suse.de>
# Date 1502609999 -7200
#      Sun Aug 13 09:39:59 2017 +0200
# Node ID a98e00eed893f62dd8349fc2894abca3aff4b33a
# Parent  41ce01b7d413b3654211da0147857e7d6a1495de
Facilitate reproducible builds
by allowing to externally hold constant the build date and time.
See
        https://reproducible-builds.org/specs/source-date-epoch/

Backport asap.

diff -r 41ce01b7d413 -r a98e00eed893 NEWS
--- a/NEWS	Sun Aug 13 09:39:56 2017 +0200
+++ b/NEWS	Sun Aug 13 09:39:59 2017 +0200
@@ -48,6 +48,12 @@
           https://github.com/akrzemi1/Optional
   where only "optional.hpp" is needed.
 
+- The environment variable SOURCE_DATE_EPOCH overrides the build
+  timestamp as recorded by the signatures.  See
+          https://reproducible-builds.org/specs/source-date-epoch/
+  for details.
+
+
 
 * Version 4.2  "Compressor Road"
 
diff -r 41ce01b7d413 -r a98e00eed893 src/DefaultSig.pm
--- a/src/DefaultSig.pm	Sun Aug 13 09:39:56 2017 +0200
+++ b/src/DefaultSig.pm	Sun Aug 13 09:39:59 2017 +0200
@@ -109,9 +109,10 @@
 sub update_date_and_time {
     my $self = shift;
 
+    my $now = $ENV{SOURCE_DATE_EPOCH} || time;
     my ($second, $minute, $hour,
         $day_of_month, $month, $year,
-        $day_of_week) = $self->is_using_gmt() ? gmtime : localtime;
+        $day_of_week) = $self->is_using_gmt() ? gmtime($now) : localtime($now);
 
     $self->{DATE} = $self->format_date($day_of_month, $month, $year + 1900, $day_of_week,
                                        $self->weekdays->[$day_of_week],