How to reduce the vertical distance before a \begin{addmargin}

Question

I have the following texts. My problem is that between my text and myothertext a distance is inserted that is about the equal of a full line. As I want to avoid this but not sure as to how I can do that my question is how can I reduce this vertical distance?

Mytext
\begin{addmargin}[0.3cm]{0cm}
    MyOtherText
\end{addmargin}

for the documentclass I'm using its this one:

\documentclass[8pt,a4paper,BCOR10mm,DIV11,toc=listof,parskip=full, openany]{scrbook}

Answer 1

\documentclass[parskip=full,]{scrartcl}
\makeatletter
\let\@addmarginORIG\@addmargin
\renewcommand*\@addmargin{%
    \vspace{-\bigskipamount}
    \@addmarginORIG}
\makeatother
\begin{document}

Mytext
\begin{addmargin}[0.3cm]{0cm}
        MyOtherText
\end{addmargin}

\end{document}

Answer 2

You are using parskip=full and scrbook duly obeys it: addmargin starts a new paragraph and so it is separated from the preceding paragraph with a full parskip.

If you want to remove the parskip in your addmargin environment, I suggest you to define a new environment.

\documentclass[
  parskip=full
]{scrartcl}

\newenvironment{thomasaddmargin}
 {\setlength{\parskip}{0pt plus 1pt}\addmargin}
 {\endaddmargin}

\begin{document}

Mytext
\begin{thomasaddmargin}[0.3cm]{0cm}
MyOtherText
\end{thomasaddmargin}

Mytext

Mytext

\end{document}

If you want to follow the “remove the vertical space approach”, you have to patch the right command, which is not \@addmargin, but the internal one called by it. This is easy with xpatch; note that the glue to remove is \parskip, not \bigskipamount.

\documentclass[
  parskip=full
]{scrartcl}

\usepackage{xpatch}

\makeatletter
\pretocmd{\@addmargin}{\vspace{-\parskip}}{}{}
\makeatother

\begin{document}

Mytext
\begin{addmargin}[0.3cm]{0cm}
MyOtherText
\end{addmargin}

Mytext

Mytext

\end{document}

The output is the same because there is only one paragraph in the addmargin environment.

The difference between the two solutions is that in the former no parskip will be used between paragraphs inside addmargin; the normal parskip will be used in the latter solution. Take your pick.

Final exhortation: don't use parskip=full.