From e3992118c870507c76684bcd756f05ad9f2dada7 Mon Sep 17 00:00:00 2001
From: Witold Filipczyk <witekfl@poczta.onet.pl>
Date: Mon, 28 Mar 2022 20:46:07 +0200
Subject: [PATCH] [configure.ac] Added --enable-reproducible and
 --with-source-date-epoch=TIME

Example of usage:
./autogen.sh
./configure ... \
--enable-reproducible \
--with-source-date-epoch=$(git log -1 --pretty=%ct)

make
make -C doc html
---
 Makefile.config.in             |  2 +-
 configure.ac                   | 10 ++++++++++
 doc/tools/asciidoc/asciidoc.py |  3 ++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Makefile.config.in b/Makefile.config.in
index f68c8fcfe..5b2e8ada5 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -50,7 +50,7 @@ INSTALL_SCRIPT = @INSTALL_SCRIPT@
 
 host = @host@
 
-ASCIIDOC = @PYTHON3@ $(top_srcdir)/doc/tools/asciidoc/asciidoc.py
+ASCIIDOC = LANG=C LANGUAGE=en CONFIG_REPRODUCIBLE=@CONFIG_REPRODUCIBLE@ SOURCE_DATE_EPOCH=@SOURCE_DATE_EPOCH@ @PYTHON3@ $(top_srcdir)/doc/tools/asciidoc/asciidoc.py
 ASCIIDOC_FLAGS = --unsafe
 AWK = @AWK@
 CATALOGS = @CATALOGS@
diff --git a/configure.ac b/configure.ac
index 1321c5d3a..1791120ab 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1600,12 +1600,22 @@ EL_ARG_ENABLE(CONFIG_UTF8, utf-8, [UTF-8],
 EL_ARG_DEPEND(CONFIG_COMBINE, combining, [CONFIG_UTF8:yes HAVE_WCWIDTH:yes], [Combining characters],
 	      [  --enable-combining      support Unicode combining characters (experimental)])
 
+EL_ARG_ENABLE(CONFIG_REPRODUCIBLE, reproducible, [Reproducible builds],
+	      [  --enable-reproducible   enable reproducible build])
+
 AC_ARG_ENABLE(weehoofooboomookerchoo,
               [
     Also check out the features.conf file for more information about features!
 	      ],
 	      [AC_MSG_ERROR(Are you strange, or what?)])
 
+SOURCE_DATE_EPOCH=
+AC_ARG_WITH(source-date-epoch,    [  --with-source-date-epoch=[TIME]
+                          set source date epoch for reproducible builds],
+            [SOURCE_DATE_EPOCH="$withval"])
+
+AC_SUBST(SOURCE_DATE_EPOCH)
+
 
 # ===================================================================
 # Decide whether to use TRE
diff --git a/doc/tools/asciidoc/asciidoc.py b/doc/tools/asciidoc/asciidoc.py
index a488df5ef..f1e08fac1 100755
--- a/doc/tools/asciidoc/asciidoc.py
+++ b/doc/tools/asciidoc/asciidoc.py
@@ -1061,7 +1061,8 @@ class Document:
         self.safe = True        # Default safe mode.
     def init_attrs(self):
         # Set implicit attributes.
-        if os.environ.get('CONFIG_REPRODUCIBLE', ''):
+        repro = os.environ.get('CONFIG_REPRODUCIBLE', '')
+        if repro and repro != 'no':
             d = time.gmtime(int(os.environ.get('SOURCE_DATE_EPOCH', time.time())))
             self.attributes['localdate'] = time.strftime('%d-%b-%Y',d)
             s = time.strftime('%H:%M:%S %z',d)