Weird asterisk in ToC and section* not working when using siunitx

Question

I have a weird problem with siunitx and redefining section. Here is a screenshot of the problem:

As you can see, an asterisk appears in the ToC, aswell as the \section* command not working properly. The heading will be a star, and the actual heading goes into the text. It seems like the \section* command interprets the asterisk as the heading, and ignores the rest. So the asterisk in the ToC is more of a symptom...

Here is a MWE (rather MNWE):

main.tex

\documentclass{styles/diplclass1} 
\begin{document}

\tableofcontents
\section*{Starheading}
asdf

\section{Normal heading}
\end{document}

styles/diplclass1.cls

\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{styles/diplclass1}
\LoadClass[a4paper,11pt,titlepage,oneside]{scrbook}

\usepackage{siunitx}

\renewcommand{\section}{%
  \@startsection{section}%
  {1}
  {0mm}
  {2ex plus 1ex minus 1ex}
  {0.5ex plus 0.5ex minus 0.5ex}
  {\Large\bfseries}
}

Please note: I need to redefine sections, because I apply some styles there. Also, I need to use siunitx. I have not found anything when searching for this problem, except some issues with bibliography which seem to be related, as well as the fact, that redefining \section is okay for \section*, because \@startsection takes care of the asterisk version.

As soon as I remove the siunitx import, or the section redefinition, it works as expected. How can I redefine the section style, and use siunitx aswell? Does anyone have an idea why this problem occurs?

have you tried \RequirePackage instead of \usepackage? (Cf. What's the difference between \RequirePackage and \usepackage?) — ebosi, Apr 11 '16 at 07:40
I just did, it does not seem change anything. But thanks for the heads up — CharlyDelta, Apr 11 '16 at 07:42
@ebo the two commands are \let equal to each other so it is not going to make any difference there. — David Carlisle, Apr 11 '16 at 15:08
@DavidCarlisle Yep, I've seen it after Ulrike's answer... but didn't deleted my comment since Christian answered it. Anyway, my hint didn't helped at all indeed. :-s. — ebosi, Apr 11 '16 at 15:26

Ulrike Fischer · Accepted Answer · 2016-04-11T08:00:27.053

7

Don't use \@startsection in the KOMA-classes, the definition of the sectioning commands in KOMA are different. Use the tools offered by the class:

\documentclass{scrbook}

\usepackage{siunitx}

\RedeclareSectionCommand[
  beforeskip=2ex plus 1ex minus 1ex,
  afterskip=0.5ex plus 0.5ex minus 0.5ex,
  font=\Large\bfseries]{section}

\begin{document}

\tableofcontents
\section*{Starheading}
asdf

\section{Normal heading}
\end{document}

Addition:

Normally KOMA would warn you when you do such a redefinition and fallback to another redefition. But through siunitx you are loading the amsgen package which redefines \@ifstar and now the test of KOMA fails.

edited Apr 11 '16 at 08:00

answered Apr 11 '16 at 07:46

Ulrike Fischer

327,261

Thanks for your answer, I didn't know about that. But when I replace my previous renewcommand with the KOMA RedeclareSectionCommand, I get the error: Undefined control sequence: \RedeclareSectonCommand. I guess it means, that my srcbook package is outdated, doesn't it? – CharlyDelta Apr 11 '16 at 07:54
@ChristianDreher: Yes. – Ulrike Fischer Apr 11 '16 at 07:57
After updating koma-script it worked like a charm. Thank you very much for your qualified help :)) – CharlyDelta Apr 11 '16 at 08:36

Weird asterisk in ToC and section* not working when using siunitx

1 Answers1

Addition: