RE: [PATCH 1/2] doc: add an option to have Asciidoctor build man pages directly

> From: Felipe Contreras <felipe.contreras@gmail.com>
> 
> Asciidoctor contains a converter to generate man pages.  In some
> environments, where building only the manual pages and not the other
> documentation is desired, installing a toolchain for building
> DocBook-based manual pages may be burdensome, and using Asciidoctor
> directly may be easier, so let's add an option to build manual pages
> using Asciidoctor without the DocBook toolchain.
> 
> We generally require Asciidoctor 1.5, but versions before 1.5.3 didn't
> contain proper handling of the apostrophe, which is controlled normally
> by the GNU_ROFF option.  This option for the DocBook toolchain, as well
> as newer versions of Asciidoctor, makes groff output an ASCII apostrophe
> instead of a Unicode apostrophe in text, so as to make copy and pasting
> commands easier.  These newer versions of Asciidoctor detect groff and
> do the right thing in all cases, so the GNU_ROFF option is obsolete in
> this case.
> 
> We also need to update the code that tells Asciidoctor how to format our
> linkgit macros so that it can output proper code for man pages.  Be
> careful to reset the font to the previous after the change.  In order to
> do so, we must reset to the previous after each font change so the
> previous state at the end is the state before our inserted text, since
> troff only remembers one previous font.
> 
> Because Asciidoctor versions before 2.0 had a few problems with man page
> output, let's default this to off for now,

> ---
> I've preserved Felipe's authorship on this patch because much of it is
> his work.  However, I have made some substantial changes here with which
> I suspect he will disagree, in addition to expanding on the commit
> message, so if he would prefer, I can reroll with the authorship
> changed.  I have no preference myself.

>  Documentation/Makefile                  | 10 ++++++++++
>  Documentation/asciidoctor-extensions.rb |  2 ++
>  Makefile                                |  3 +++
>  3 files changed, 15 insertions(+)
> 
> diff --git a/Documentation/Makefile b/Documentation/Makefile
> index 2aae4c9cbb..536d9a5f3d 100644
> --- a/Documentation/Makefile
> +++ b/Documentation/Makefile
> @@ -196,6 +196,9 @@ ASCIIDOC_EXTRA += -alitdd='&\#x2d;&\#x2d;'
>  DBLATEX_COMMON =
>  XMLTO_EXTRA += --skip-validation
>  XMLTO_EXTRA += -x manpage.xsl
> +ifdef USE_ASCIIDOCTOR_MANPAGE

> +TXT_TO_MAN = $(ASCIIDOC_COMMON) -b manpage
> +endif
>  endif
>  
>  SHELL_PATH ?= $(SHELL)

> diff --git a/Documentation/asciidoctor-extensions.rb b/Documentation/asciidoctor-extensions.rb
> index d906a00803..40fa87b121 100644
> --- a/Documentation/asciidoctor-extensions.rb
> +++ b/Documentation/asciidoctor-extensions.rb
> @@ -15,6 +15,8 @@ module Git
>            "#{target}(#{attrs[1]})</ulink>"
>          elsif parent.document.basebackend? 'html'
>            %(<a href="#{prefix}#{target}.html">#{target}(#{attrs[1]})</a>)
> +        elsif parent.document.basebackend? 'manpage'
> +          %(\\fB#{target}\\fP\\fR(#{attrs[1]})\\fP)