From f901c954d1882ef24fcf3a1642d46eb785a1863f Mon Sep 17 00:00:00 2001
From: Dominique Leuenberger <dimstar@opensuse.org>
Date: Wed, 8 May 2019 19:00:47 +0200
Subject: [PATCH 1/2] DOC: Move to DocBook 5 when using asciidoctor

DocBook 5 has been released about a decade ago. Newer versions of
asciidoctor (since version 2.x) no longer support DocBook 4.5, it
is thus time for us to move to newer support as well.
---
 contrib/subtree/Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/contrib/subtree/Makefile b/contrib/subtree/Makefile
index 6906aae..09e53b9 100644
--- a/contrib/subtree/Makefile
+++ b/contrib/subtree/Makefile
@@ -25,12 +25,13 @@ ASCIIDOC_HTML    = xhtml11
 ASCIIDOC_DOCBOOK = docbook
 ASCIIDOC_EXTRA   =
 XMLTO            = xmlto
+XMLTO_EXTRA      = --skip-validation
 
 ifdef USE_ASCIIDOCTOR
 ASCIIDOC         = asciidoctor
 ASCIIDOC_CONF    =
 ASCIIDOC_HTML    = xhtml5
-ASCIIDOC_DOCBOOK = docbook45
+ASCIIDOC_DOCBOOK = docbook5
 ASCIIDOC_EXTRA  += -I../../Documentation -rasciidoctor-extensions
 ASCIIDOC_EXTRA  += -alitdd='&\#x2d;&\#x2d;'
 endif
@@ -78,7 +79,7 @@ install-html: $(GIT_SUBTREE_HTML)
 	$(INSTALL) -m 644 $^ $(DESTDIR)$(htmldir)
 
 $(GIT_SUBTREE_DOC): $(GIT_SUBTREE_XML)
-	$(XMLTO) -m $(MANPAGE_XSL) man $^
+	$(XMLTO) -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $^
 
 $(GIT_SUBTREE_XML): $(GIT_SUBTREE_TXT)
 	$(ASCIIDOC) -b $(ASCIIDOC_DOCBOOK) -d manpage $(ASCIIDOC_CONF) \
-- 
2.24.0