From f28f0c4d8dfdfb1c173d21df6ffbe35448fada9f Mon Sep 17 00:00:00 2001
From: Zhang Peng <peng.zhang1.cn@windriver.com>
Date: Mon, 9 Mar 2026 20:10:00 +0800
Subject: [PATCH] gropdf: use SOURCE_DATE_EPOCH for reproducible builds

gropdf uses rand() to generate random font subset tags in SubTag().
Without a deterministic seed, each build produces different PDF output.

Initialize srand() with SOURCE_DATE_EPOCH when available to ensure
reproducible builds.

Upstream-Status: Submitted [https://savannah.gnu.org/bugs/?68136]

Signed-off-by: Zhang Peng <peng.zhang1.cn@windriver.com>
---
 src/devices/gropdf/gropdf.pl | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/devices/gropdf/gropdf.pl b/src/devices/gropdf/gropdf.pl
index f519a53..3a79b4c 100644
--- a/src/devices/gropdf/gropdf.pl
+++ b/src/devices/gropdf/gropdf.pl
@@ -30,6 +30,13 @@ use POSIX qw(mktime);
 use File::Spec;
 use File::Path;
 
+# Initialize random seed for reproducible builds.
+if (defined($ENV{SOURCE_DATE_EPOCH})) {
+    srand($ENV{SOURCE_DATE_EPOCH});
+} else {
+    srand();
+}
+
 use constant
 {
     WIDTH    => 0,
-- 
2.50.0