doxygen_to_devhelp: Produce Devhelp index format v2

The old version-1 format is deprecated and now produces warnings.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=106186
Reviewed-by: Philip Withnall <withnall@endlessm.com>
[smcv: Add the .devhelp2 file to .gitignore as suggested]
Signed-off-by: Simon McVittie <smcv@collabora.com>
(cherry picked from commit fa92263920)

doc/.gitignore

@@ -10,6 +10,7 @@ Makefile.in
 *.o
 api
 dbus.devhelp
+/dbus.devhelp2
 dbus-specification.html
 dbus-test-plan.html
 dbus-tutorial.html

doc/Makefile.am

@@ -98,9 +98,9 @@ doxygen.stamp: $(wildcard $(top_srcdir)/dbus/*.[ch])
 	@touch $@
 
 if DBUS_HAVE_XSLTPROC
-html_DATA += dbus.devhelp
+html_DATA += dbus.devhelp2
 
-dbus.devhelp: $(srcdir)/doxygen_to_devhelp.xsl doxygen.stamp
+dbus.devhelp2: $(srcdir)/doxygen_to_devhelp.xsl doxygen.stamp
 	$(XSLTPROC) -o $@ $< api/xml/index.xml
 endif
 

doc/doxygen_to_devhelp.xsl

@@ -11,6 +11,11 @@
   <book title="D-Bus: A system for interprocess communication"
         name="dbus"
         link="{$prefix}/api/index.html"
+        xmlns="http://www.devhelp.net/book"
+        version="2"
+        online="https://dbus.freedesktop.org/doc/"
+        author="D-Bus contributors"
+        language="c"
         >
   <chapters>
      <sub name="Tutorial" link="{$prefix}dbus-tutorial.html"/>
@@ -33,7 +38,7 @@
   <xsl:param name="link"><xsl:value-of select="$before"/>.html#<xsl:value-of select="$after"/></xsl:param>
   <xsl:if test="starts-with($name,'dbus') or starts-with($name, 'DBus')">
     <xsl:if test="starts-with($refid,'group__') and contains($refid, '_1')">
-       <function name="{$name}" link="{$prefix}api/{$link}"/>
+       <keyword xmlns="http://www.devhelp.net/book" type="function" name="{$name}" link="{$prefix}api/{$link}"/>
     </xsl:if>
   </xsl:if>
 </xsl:template>