Wrapped figure diverges from text level after sections

Question

I have a big problem. I want to print an book with reportages. Every reportage has a headline (created by the section command), a teaser and an article. The teaser should be wrapped text and should be at the same level as the article. This works when I leave out the section-command as in the first \teaser. As soon as I add the section line the teaser and the reportage level diverges. Has anyone an idea how to fix this problem? Here an example:

\documentclass{article}

\usepackage{wrapfig}

\newcommand{\teaser}[1]{\begin{wrapfigure}{l}{0.5\textwidth}\textbf{#1}\end{wrapfigure}}

\begin{document}

\teaser{sdfaasdfasdf asfasfa asdfasdf asdfasf  asfasfasdfaasdfasdf aasdfasf }
 asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfassdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf

 \section{adf}
\teaser{sdfaasdfasdf asfasfa asdfasdf asdfasf  asfasfasdfaasdfasdf aasdfasf }
 asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfassdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf asdfasdf asdfasf  asfasfasdfaasdfasdf

\end{document}

Answer 1

I don't know what's causing the odd behaviour; however, you can prevent it using a convenient vertical skip; this is not an optimum solution, since it will produce undesired results if, for example, the \teaser command starts a new page. However, since you said your reportages will always start with a headline (created with the \section command), you could give it a try:

\documentclass{article}
\usepackage{wrapfig}

\newcommand{\teaser}[1]{%
  \begin{wrapfigure}{l}{0.5\textwidth}\vspace*{-1\baselineskip}%
  \textbf{#1}\end{wrapfigure}}

\begin{document}

\section{Test section}
\teaser{teaser text teaser text teaser text teaser text teaser text teaser text} text text text  text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text text

\end{document}

Answer 2

The space is \intextsep. It is inserted before every wrapfig. You don't see it in the first teaser because it is at the start of a page where such vertical spaces disappear. intextsep is declared/defined by the latex format and it is used in floats which are inserted with "h" in the text. So if you set it globally to 0pt it will affect such floats too.

Answer 3

You can replicate your output using the titlesec package instead of wrapfig. The only puzzle with this code is that with no text after a section, the vertical spacing of the following subsection heading is wrong. This is fixed by inserting \leavevmode in between the section and the subsection.

\documentclass{article}
\usepackage{titlesec}
\usepackage[nopar]{lipsum} % for dummy text.

\titleformat{\subsection}[wrap] {\normalfont\bfseries\filright} {}{0em}{}
\titlespacing*{\subsection} {.5\textwidth}{0ex}{1pc}

\begin{document}

\section{A section}
\leavevmode % required if no text between \section and \subsection
\subsection{Lorem ipsum dolor sit amet, consectetuer adipiscing elit.}
\lipsum[1]

\end{document}