# titlesec tikz twocolumn odd behavior

In the code

\documentclass[twocolumn]{article}

\usepackage{tikz}
\usepackage{titlesec}
\usepackage{lipsum}

\titleformat{\subsection}[runin]{\bfseries}{\thesubsection}{1ex}{}[:]

\begin{document}
\section{Section}

\subsection{First subection}

\lipsum[1-3]

\subsection{Second subsection}

\end{document}


the second subsection is pushed to the next page. This does not happen when tikz isn't loaded or when the subsection isn't redefined. What causes this?

It's not a big deal since this feature disappears once one adds some text to the second subsection, but I can imagine that there are other undesirable side effects....

• Suggest: remove tikz and replace by \makeatletter \input pgfutil-common.tex \input pgfutil-latex.def \makeatother for a more minimal example. – cfr Jul 22 '17 at 1:35
• If you look at pgfutil-latex.def, you may be surprised it doesn't cause greater oddities more frequently :-). – cfr Jul 22 '17 at 1:39