We use XeLaTeX to produce Large Print and have come across an issue when trying to produce a book with quite a few Parts where we only want to show the parts in the ToC. I have reduced it down to a minimal example:
\documentclass{book}
\usepackage[english]{babel}
\begin{document}
\tableofcontents
\part[{1}]{1}
\part[{2}]{2}
\part[{3}]{3}
\part[{4}]{4}
\part[{5}]{5}
\part[{6}]{6}
\part[{7}]{7}
\part[{8}]{8}
\part[{9}]{9}
\part[{10}]{10}
\part[{11}]{11}
\part[{12}]{12}
\part[{13}]{13}
\part[{14}]{14}
\part[{15}]{15}
\part[{16}]{16}
\part[{17}]{17}
\part[{18}]{18}
\end{document}
This produces a Contents page which starts on page 2 as it can't fit on page 1 and doesn't want to split. In reality I'm using memoir and 25pt with 7 parts, but this example produces the same result. I've tried it in texlive 2014. Is there a work around that doesn't involve manually inserting a ToC break where it needs to be. This is part of an automated system and the user doesn't have access to the TeX code, so I need a way to allow the page to split automatically.

\chapters in each\part. Is\partreally the correct subdivision for your purposes? – Andrew Swann Nov 11 '14 at 13:21\chapters but then I have\maxtocdepth{part}so it gets the same result. – Paul Wood Nov 12 '14 at 11:22chapterlevel entries. Not the most elegant solution, though. – cfr Jan 12 '17 at 02:04