How can I configure latex to try to break at a sectioning command before it breaks a paragraph?

Question

MWE

\documentclass[paper=a4]{scrartcl}
\usepackage{lipsum}
\begin{document}
    \section{a}
    \lipsum[1-2]
    \section{b}
    \lipsum[3-4]
    \subsection{c}
    \lipsum[5]
\end{document}

The example above will break the paragraph in the subsection c in half.

I would like latex to, when it needs a page break,

• Break at the subsection level(or whatever the deepest sectioning level in that location was)
• If there are multiple subsections on that page and breaking at that level will make the document require another break at a paragraph later on(because it would shift everything), try to break at an upper level(section, subsection) instead.

Is there a package or a configuration setting that would supply this algorithm? Or if I were to place pagebreak commands in some clever way, would it achieve this effect, semi-automatically?

Or in other words, I want latex to leave space at the bottom instead of splitting paragraphs, and I am also wondering if it can be clever about this by breaking a section early to avoid having to break a subsection later on. The latter part is also important, only achieving the former is relatively easy.

I know that I can do this by inserting a \newpage etc. above the \subsection{c} line, I am not looking for the plain breaks.

Please feel free to share a solution even if it is specific to a rendering engine or a different latex implementation.

Thanks in advance.

Answer 1

You can avoid having a paragraph split with the \interlinepenalty. I just added one line to your example:

\documentclass[paper=a4]{scrartcl}
\interlinepenalty=10000
\usepackage{lipsum}
\begin{document}
    \section{a}
    \lipsum[1-2]
    \section{b}
    \lipsum[3-4]
    \subsection{c}
    \lipsum[5]
\end{document}