Check for stylesheets required for man page

Macros copied from gtk-doc.

https://bugzilla.gnome.org/show_bug.cgi?id=743255

configure.ac

@@ -95,8 +95,14 @@ AS_IF([test "x$enable_man_pages" != "xno"],
       [AC_PATH_PROG([XSLTPROC], [xsltproc])
        AS_IF([test "xac_cv_path_XSLTPROC" = "x"], [have_xsltproc=no],
              [have_xsltproc=yes])
-dnl TODO: Also check for the required stylesheets.
-       AS_IF([test "x$have_xsltproc" = "xyes"],
+       JH_CHECK_XML_CATALOG([-//OASIS//DTD DocBook XML V4.2//EN],
+                            [DocBook XML DTD V4.2], [have_docbookdtd=yes],
+                            [have_docbookdtd=no])
+       JH_CHECK_XML_CATALOG([http://docbook.sourceforge.net/release/xsl/current/html/refentry.xsl],
+                            [DocBook XSL Stylesheets], [have_docbookxsl=yes],
+                            [have_docbookxsl=no])
+       AS_IF([test "x$have_xsltproc" = "xyes" -a "x$have_docbookdtd" = "xyes" \
+              -a "x$have_docbookxsl" = "xyes"],
              [have_manutils=yes],
              [AS_IF([test "x$enable_man_pages" = "xyes"],
                     [AC_MSG_ERROR([man page requested but required utilities were not found])])

m4/gtkdoc_jh_check_xml_catalog.m4

@@ -0,0 +1,16 @@
+dnl Checks if a particular URI appears in the XML catalog
+dnl Usage:
+dnl	JH_CHECK_XML_CATALOG(URI, [FRIENDLY-NAME], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+AC_DEFUN([JH_CHECK_XML_CATALOG],
+[
+	AC_REQUIRE([JH_PATH_XML_CATALOG],[JH_PATH_XML_CATALOG(,[:])])dnl
+	AC_MSG_CHECKING([for ifelse([$2],,[$1],[$2]) in XML catalog])
+	if $jh_found_xmlcatalog && \
+		AC_RUN_LOG([$XMLCATALOG --noout "$XML_CATALOG_FILE" "$1" >&2]); then
+		AC_MSG_RESULT([found])
+		ifelse([$3],,,[$3])
+	else
+		AC_MSG_RESULT([not found])
+		ifelse([$4],,[AC_MSG_ERROR([could not find ifelse([$2],,[$1],[$2]) in XML catalog])],[$4])
+	fi
+])

m4/gtkdoc_jh_path_xml_catalog.m4

@@ -0,0 +1,61 @@
+dnl Checks the location of the XML Catalog
+dnl Usage:
+dnl	JH_PATH_XML_CATALOG([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl Defines XMLCATALOG and XML_CATALOG_FILE substitutions
+AC_DEFUN([JH_PATH_XML_CATALOG],
+[
+	dnl check for the presence of the XML catalog
+	AC_ARG_WITH([xml-catalog],
+		AS_HELP_STRING([--with-xml-catalog=CATALOG],
+		[path to xml catalog to use]),,
+		[with_xml_catalog=''])
+	AC_MSG_CHECKING([for XML catalog])
+	if test -n "$with_xml_catalog"; then
+		dnl path was explicitly given.  check that it exists.
+		if test -f "$with_xml_catalog"; then
+			jh_found_xmlcatalog=true
+		else
+			jh_found_xmlcatalog=false
+		fi
+	else
+		dnl if one was not explicitly specified, try some guesses
+		dnl we look first in /etc/xml/catalog, then XDG_DATA_DIRS/xml/catalog
+		if test -z "$XDG_DATA_DIRS"; then
+			dnl if we have no XDG_DATA_DIRS, use the default
+			jh_xml_catalog_searchdirs="/etc:/usr/local/share:/usr/share"
+		else
+			jh_xml_catalog_searchdirs="/etc:$XDG_DATA_DIRS"
+		fi
+		jh_found_xmlcatalog=false
+		dnl take care to iterate based on ':', allowing whitespace to appear in paths
+		jh_xml_catalog_saved_ifs="$IFS"
+		IFS=':'
+		for d in $jh_xml_catalog_searchdirs; do
+			if test -f "$d/xml/catalog"; then
+				with_xml_catalog="$d/xml/catalog"
+				jh_found_xmlcatalog=true
+				break
+			fi
+		done
+		IFS="$jh_xml_catalog_saved_ifs"
+	fi
+	if $jh_found_xmlcatalog; then
+		AC_MSG_RESULT([$with_xml_catalog])
+	else
+		AC_MSG_RESULT([not found])
+	fi
+	XML_CATALOG_FILE="$with_xml_catalog"
+	AC_SUBST([XML_CATALOG_FILE])
+
+	dnl check for the xmlcatalog program
+	AC_PATH_PROG(XMLCATALOG, xmlcatalog, no)
+	if test "x$XMLCATALOG" = xno; then
+		jh_found_xmlcatalog=false
+	fi
+
+	if $jh_found_xmlcatalog; then
+		ifelse([$1],,[:],[$1])
+	else
+		ifelse([$2],,[AC_MSG_ERROR([could not find XML catalog])],[$2])
+	fi
+])