Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
To:     Jonathan Corbet <corbet@lwn.net>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     "Wu X.C." <bobwxc@email.cn>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, Akira Yokosawa <akiyks@gmail.com>
From:   Akira Yokosawa <akiyks@gmail.com>
Subject: [PATCH] docs: pdfdocs: Prevent column squeezing by tabulary
Message-ID: <277d68fa-c96a-0ccb-6ce0-4d314851d9fe@gmail.com>
Date:   Sun, 30 May 2021 00:19:14 +0900
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Setting a reasonable width to \tymin prevents column squeezing
by tabulary.
Width of 20em works well in almost all the tables still in the
ascii-art format.

Excerpt from tabulary package documentation at [1]:

    To stop very narrow columns being too 'squeezed' by this process
    any columns that are narrower than \tymin are set to their natural
    width.

[1]: https://mirrors.ctan.org/macros/latex/contrib/tabulary/tabulary.pdf

Note: Sphinx has its own default value of \tymin set in
sphinxlatextables.sty (Sphinx 4.0.2) and sphinxmulticell.sty
(Sphinx 2.4.4) as follows:

    \setlength{\tymin}{3\fontcharwd\font`0 }

, which is not sufficient for kernel-doc.

Tested against Sphinx versions 2.4.4 and 4.0.2.

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
---
Hi all,

This is another attempt to improve pdfdocs output.
As far as I see, I don't see any obvious regression by
this change.

The effect of this change can be seen in (not limited to)
the MODULE_LICENSE section in process.pdf (pages 10 and 11).

I'd like to know this change looks reasonable to you.

Any feedback is welcome!

        Thanks, Akira

--
 Documentation/conf.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/conf.py b/Documentation/conf.py
index 25aa00c707b0..a05225056e08 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -353,6 +353,8 @@ latex_elements = {
 
     # Additional stuff for the LaTeX preamble.
     'preamble': '''
+	% Prevent column squeezing of tabulary.
+	\\setlength{\\tymin}{20em}
         % Use some font with UTF-8 support with XeLaTeX
         \\usepackage{fontspec}
         \\setsansfont{DejaVu Sans}
-- 
2.17.1