如何强制 LaTeX 将章节/小节标题及其下方的一行保留在当前页面的底部？

Question

默认情况下，LaTeX 允许在节/小节标题后的前两行段落后进行分页，但我想将节标题及其下方的一行保留在当前页面的底部。怎么做？
请注意，我不想使用任何其他软件包，例如 etoolbox 或 needspace。
这是我的 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}

Answer 1

无需任何附加软件包，在序言中添加以下几行

\makeatletter
\renewcommand\@afterheading{%
  \@nobreaktrue
  \everypar{%
    \if@nobreak
      \@nobreakfalse
      \clubpenalty 1
      \if@afterindent \else
        {\setbox\z@\lastbox}%
      \fi
    \else
      \clubpenalty 1
      \everypar{}%
    \fi}}
\makeatother

梅威瑟：

\documentclass{book}
\usepackage[showframe]{geometry}% just for this example
\usepackage{lipsum}
\newcommand{\dummy}{This is a test }

\makeatletter
\renewcommand\@afterheading{%
  \@nobreaktrue
  \everypar{%
    \if@nobreak
      \@nobreakfalse
      \clubpenalty 1
      \if@afterindent \else
        {\setbox\z@\lastbox}%
      \fi
    \else
      \clubpenalty 1
      \everypar{}%
    \fi}}
\makeatother

\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} 

输出：

Answer 2

\documentclass{book}
\usepackage[showframe]{geometry}% just for this example
\usepackage{lipsum}
\newcommand\dummy{This is a test }
\widowpenalty=-1000 %%%%%%%%%%%%%%%%%%%%%%%%%%
\clubpenalty=-1000  %%%%%%%%%%%%%%%%%%%%%%%%%%
\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}