Underline overfull \hbox

Question

I am getting the following Overfull \hbox (0.10945pt too wide) in paragraph at lines 12--13. How could I prevent this?

I am using \, inside \dotuline because I want to use a little bit longer dotted underline.

\documentclass[12pt]{report}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[left=2.5cm, right=2.5cm, top=2.5cm, bottom=2.5cm, noheadfoot]{geometry}
\usepackage[dot]{dashundergaps}

\setlength\parindent{0pt}

\begin{document}

Lorem \dotuline{\,\,LoremLoremLoremLoremLoremLoremLoremLorem LoremLoremLoremLoremLorem\,\,} Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem Lorem

\end{document}

UPDATE

\documentclass[12pt]{report}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[left=2.5cm, right=2.5cm, top=2.5cm, bottom=2.5cm, noheadfoot]{geometry}
\hyphenation{Lor-em}
\usepackage[dot]{dashundergaps}

\setlength\parindent{0pt}

\begin{document}

Lorem \dotuline{\,\,Lor\-emLor\-emLor\-emLor\-emLor\-emLor\-emLor\-em} Lor\-em Lor\-emLor\-emLor\-emLor\-emLor\-emLor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em Lor\-em

\end{document}

In this case I am getting the following Overfull \hbox (20.50162pt too wide) in paragraph at lines 13--14

Answer 1

Your string of Lorems simply stretches past the line limit, and TeX can't find a good place to end the line (before the Lorem would add too much space, and inserting the break afterward, which it does, overfills the hbox). (This is unrelated to your \dotuline).

Try locating which "Lorem" TeX inserts a line break after, and insert a discretionary hyphen (\-) in it somewhere to tell TeX to allow a break there (eg Lor\-em).

You could also add \hyphenation{Lor-em} to your preamble to let TeX know that whenever it encounters a Lorem it needs to break up, it can insert a discretionary hyphen between the r and e.