Disallow hyphenated words go into the margin in section heading

Question

I had a long section heading that the last word will hyphenate at the end, which goes into the margin.

Minimal working example:

\documentclass{article}
\usepackage[english]{babel}
\usepackage{blindtext}
\begin{document}
\subsection{longlonglong wordswordswordwords that will cause problem}
\blindtext
\end{document}

produces:

MWE output

I don't want the problem be hyphenated and want it to break line before the last word. I tried three ways:

1. Manullly add \\. This produces the desired output but it's dirty and bad: the pdf bookmark do not recognize \\, the heading may fit into TOC but it just breaks, I may want to switch to double column or other document class.

2. I tried the solutions in this question. That is, using nohyphens provided by hyphenat package, but things gets worse:

nohyphens example

3. use penalty for hyphen:

   \subsection{
   \begingroup
   \hyphenpenalty 10000
   \exhyphenpenalty 10000
   longlonglong wordswordswordwords that will cause problem
   \endgroup
   }
   

result:

hyphenpenalty example

Yeah it breaks at the last word but the first line becomes right-justified. I want them to be left-justified (and it should).

Hope some want can show me some workaround. Thanks in advance!

Answer 1

in my opinion (agreed by the american math society as demonstrated in their document classes), "standalone" headings shouldn't be justified, but ragged right. this redefinition of the basic article section command adds only \raggedright at the end. the basic latex definition of \raggedright suppresses hyphenation as well as omitting the stretching of continued lines to the full text width. this operates only on the section heading itself, and does not affect the table of contents (though an argument can be made there as well for "controlled" ragged right (i.e., done in such a way as to not affect the positioning of page numbers).

\makeatletter
\renewnewcommand\section{\@startsection {section}{1}{\z@}%
                                   {-3.5ex \@plus -1ex \@minus -.2ex}%
                                   {2.3ex \@plus.2ex}%
                                   {\normalfont\Large\bfseries\raggedright}}
\makeatother

Answer 2

\documentclass{article}
\usepackage[english]{babel}
\usepackage{blindtext}
\begin{document}
\subsection{\sloppy longlonglong wordswordswordwords that will cause problem}
\blindtext
\end{document}

Answer 3

You can use a \linebreak command to force the line break and an \mbox to prevent the problematic word from being hyphenated; the optional argument of the sectioning command can then be used to prevent problems in the ToC, in possible headings using the title, and in the bookmarks:

\documentclass{article}
\usepackage[english]{babel}
\usepackage{hyperref}
\usepackage{blindtext}
\begin{document}
\subsection[longlonglong wordswordswordwords that will cause problem]{longlonglong wordswordswordwords that will cause\linebreak \mbox{problem}}
\blindtext
\end{document}