Footnote runs onto second page

Question

I have a footnote that begins on one page but the text runs over onto the footnote section of the page afterwards. Any way to fix this? I'm using footmisc and the oneside book class.

Answer 1

To find broken footnotes (first step before fixing, if it isn't done globally), you can use the fnbreak package.

Answer 2

The TeX FAQ has some information on this.

The easiest (and most brutal) thing they suggest is setting \interfootnotelinepenalty=10000, which will prevent the footnote from breaking across pages.

Alternatively, they suggest adjusting the space on the page (using \enlargethispage{<length>}), to force the line with the footnote onto the next page.

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And here's an example what an MWE could look like, which makes it possible to try out different solutions:

\documentclass[oneside]{book}
\usepackage{lipsum}
% \usepackage[splitrule]{footmisc} %% The splitrule option draws a full width rule above the continued part of the footnote as a visual cue to readers.

% \interfootnotelinepenalty=10000 %% Completely prevent breaking of footnotes

\begin{document}
\lipsum[1-3]
\lipsum[1]
New paragraph, which is really long, so long in fact that it spans more than one line. New paragraph, which is really long, so long in fact that it spans more than one line.
\footnote{Here's a really long footnote that will probably be longer than one line, which could help to show the problematic behaviour.} % \enlargethispage{-\baselineskip} %% move one line (and the footnote) onto the next page
\lipsum
\end{document}

Answer 3

Since you're already using the footmisc package, you may want to load it with the option splitrule. Doing so will place a full-linelength line ("rule" in typographic jargon) above the split-off part of a footnote that's split across two pages. This is a frequently-used solution in the publishing industry to indicate to readers that the footnote material at the bottom of a page is a continuation of something that was started on the preceding page.

More information on the subject of split footnotes and how to best deal with them is available in Why does LaTeX split footnotes across pages? from the UK TeX FAQ list.