From 2146f4a44fbee1e3aef12e56ae3d904e793090cd Mon Sep 17 00:00:00 2001
From: Vagrant Cascadian <vagrant@reproducible-builds.org>
Date: Fri, 26 Feb 2021 19:10:10 +0000
Subject: [PATCH] XMPSchemaAdapter.java: Use UTC timezone when
 SOURCE_DATE_EPOCH is set.

SOURCE_DATE_EPOCH specifies the timestamp, but needs to be rendered in
UTC timezone to ensure reproducible builds.

https://reproducible-builds.org/docs/source-date-epoch/

This is a follow-up to https://bugs.debian.org/978499 in apache fop,
as there is no way for fop itself to pass the timezone information for
some values.
---
 .../java/org/apache/xmlgraphics/xmp/XMPSchemaAdapter.java    | 5 +++++
 1 file changed, 5 insertions(+)

--- a/src/main/java/org/apache/xmlgraphics/xmp/XMPSchemaAdapter.java
+++ b/src/main/java/org/apache/xmlgraphics/xmp/XMPSchemaAdapter.java
@@ -157,6 +157,11 @@
      * @return the formatted date
      */
     public static String formatISO8601Date(Date dt) {
+        // https://reproducible-builds.org/docs/source-date-epoch/
+        String source_date_epoch = System.getenv("SOURCE_DATE_EPOCH");
+        if (source_date_epoch != null) {
+            return formatISO8601Date(dt, TimeZone.getTimeZone("Etc/UTC"));
+        }
         return formatISO8601Date(dt, TimeZone.getDefault());
     }