By default, LaTeX allows a page break after the first two lines of paragraphs following section/subsection headings, but I would like to keep the section heading with even one line below it at the bottom of the current page. How to do it?
Please note that I'd prefer not to use any additional packages such as etoolbox or needspace.
Here is my MWE:
\documentclass{book}
\usepackage[showframe]{geometry}% just for this example
\usepackage{lipsum}
\newcommand{\dummy}{This is a test }
\begin{document}
\lipsum[1-6]
\section{bla}
This is a test This is a test This is a test This is a test
This is a test This is a test This is a test
This is a test
\end{document}