From e13df516cb032ea3ebe103228fbb3ef12df4adfb Mon Sep 17 00:00:00 2001
From: "Bernhard M. Wiedemann" <bwiedemann@suse.de>
Date: Fri, 6 Dec 2024 08:52:25 +0100
Subject: [PATCH] Make tarball creation deterministic

for reproducible builds.

The reproducible code-path assumes GNU tar is used.
If $SOURCE_DATE_EPOCH is not set, it should work the same as before.
---
 resources/bitmaps_png/CMakeLists.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/resources/bitmaps_png/CMakeLists.txt b/resources/bitmaps_png/CMakeLists.txt
index 27d7cfd8a9..0dfe60e820 100644
--- a/resources/bitmaps_png/CMakeLists.txt
+++ b/resources/bitmaps_png/CMakeLists.txt
@@ -897,8 +897,12 @@ else()
     set( TAR_OUTPUT_FILE "${BITMAP_ARCHIVE_PATH}" )
 endif()
 
+set( TARFLAGS cfz )
+if( DEFINED ENV{SOURCE_DATE_EPOCH} )
+    set( TARFLAGS --sort=name --mtime=@$ENV{SOURCE_DATE_EPOCH} --clamp-mtime --owner=0 --group=0 --numeric-owner --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime -czf )
+endif()
 add_custom_target( bitmap_archive ALL
-    COMMAND ${TAR} cfz "${TAR_OUTPUT_FILE}" .
+    COMMAND ${TAR} ${TARFLAGS} "${TAR_OUTPUT_FILE}" .
     DEPENDS ${ALL_PNGS}
     BYPRODUCTS ${BITMAP_ARCHIVE_PATH}
     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/png