Unwanted extra lines appearing in bibliography

When I compiled a very lengthy paper with a lengthy bibliography, I noticed that at some places in the bibliography, an extra line had been entered between entries:

I tried to cut down the document and the bibliography to isolate what caused the thing by deleting pieces and compiling. This took me several hours, and the below example was the minimal example I came up with. What I'm trying to say is, I'm aware that the example isn't perhaps "minimal," but I really tried to make it as small as possible.

I have seen this problem in my bibliographies with different fonts, but since the problem seems related to spacing, the problem only appear while using the bibliography in the minimal example if I compile it with the font Brill Roman, which can be downloaded here.

I'm compiling with xelatex and bibtex with backend biber on Mac OS Mavericks.

Does anyone know what might be the problem here?

This is the document:

\documentclass[utf8,12pt,letterpaper]{article}
\usepackage{fontspec}
\setmainfont{Brill Roman}
\usepackage[authordate,strict,isbn=false,backend=biber,bibencoding=utf8,hyperref=true,noibid,annotation]{biblatex-chicago}
%The following is for automatic sorting of references (by Guido at http://tex.stackexchange.com/questions/84020/automatic-assignment-of-references-to-bibliography-categories-depending-on-origd) :
\defbibcheck{pre}{
\iffieldint{origyear}
{\ifnumless{\thefield{origyear}}{1911}
{}
{\skipentry}
}
{\iffieldint{year}
{\ifnumless{\thefield{year}}{1911}
{}
{\skipentry}
}
{\skipentry}
}
}

\defbibcheck{post}{
\iffieldint{origyear}
{\ifnumless{1910}{\thefield{origyear}}
{}
{\skipentry}
}
{\iffieldint{year}
{\ifnumless{1910}{\thefield{year}}
{}
{\skipentry}
}
{
\skipentry %comment out this line if unknown date check is not used.
}
}
}

\defbibcheck{dateunknown}{
\ifboolexpr{
test {\iffieldundef{year}}
and
test {\iffieldundef{origyear}}
}
{}
{\skipentry}
}
%End of automatic sorting
\addbibresource{bibliographySpacing2.bib}
\begin{document}
\nocite{*}
\part*{Bibliography}\addcontentsline{toc}{part}{Bibliography}
\printbibliography[heading=subbibintoc,check=dateunknown,title={Undated Works}] \clearpage \printbibliography[heading=subbibintoc,check=pre,title={Works Written Before 1911}] \clearpage \printbibliography[heading=subbibintoc,check=post,title={Works Written After 1911}]
\end{document}


And this is bibliographySpacing2.bib:

@book{Cawdry1604ATableAlphabeticall,
author = {Cawdry, Robert},
title = {A table alphabeticall},
address = {London},
publisher = {Edmund Weauer},
date = {1604}
}

@book{Klaproth1823Asia,
address = {Paris},
title = {Asia Polyglotta},
publisher = {A. Schubart},
author = {Klaproth, Julius},
date = {1823}
}

@book{Klaproth18261828Memoires,
author = {Klaproth, Julius},
title = {Mémoires relatifs à l'Asie, contenant des recherches historiques, géographiques et philologiques sur les peuples de l'Orient},
shorttitle = {Mémoires relatifs à l'Asie},
address = {Paris},
publisher = {Dondey-Dupré, père et fils},
date = {1826},%/1828},
volumes = {3}
}

@book{Laufer1908Skizze,
title = {Skizze der manjurischen Literatur},
date = {1908},
note = {extrait de la Revue orientale},
author = {Laufer, Berthold}
}

@book{LauferNDSkizze,
title = {Skizze der manjurischen Literatur},
note = {extrait de la Revue orientale},
author = {Laufer, Berthold}
}

@review{KuhnSherman1972ReviewContributionsToAHistoryOfAlphabetization,
author = {Kuhn, {Sherman M.}},
title = {\bibstring{reviewof} \mkbibemph{Contributions to a History of Alphabetization in Antiquity and the Middle Ages} \bibstring{by} Lloyd W. Daly},
shorttitle = {\bibstring{reviewof} \mkbibemph{Contributions to a History of Alphabetization}},
journal = {Medieval Academy of America},
year = {1972},
volume = {47},
number = {2},
pages = {300--3}
}

@book{KennedyGeorge1941SerianArrangementOfChineseCharacters,
author = {Kennedy, {George A.}},
title = {Serial Arrangement of Chinese Characters},
publisher = {Department of Oriental Studies, Yale university},
%    date = {1948},
date = {1941},
%    edition = {\autocap{r}evised 2\textsuperscript{nd} edition},
address = {\emph{S.l.}}
}

@book{Cawdry1604ATableAlphabeticall,
author = {Cawdry, Robert},
title = {A table alphabeticall},
address = {London},
publisher = {Edmund Weauer},
date = {1604}
}

@book{Cawdry1604ATableAlphabeticall,
author = {Cawdry, Robert},
title = {A table alphabeticall},
address = {London},
publisher = {Edmund Weauer},
date = {1604}
}

@book{Strahlenberg1730DasNordOst,
author = {Strahlenberg, {Philipp Johann von}},
title = {Das nord- und ostliche Theil von Europa und Asia},
address = {Stockholm},
date = {1730},
publisher = {In Verlegung des Autoris},
edition = {\autocap{m}icrofilm of printed edition}
}

-

1 Answer

First of all, note that you have some strange accented characters in your .bib file. For example é is the combination of a normal e (U+0065) plus a "Combining acute accent" character (U+0301), instead of the normal accented e é (U+00E9).

Having said that, notice that the compilation returns first an "Overfull \hbox" warning caused by the word "géographiques" in your .bib file and then an "Underfull \hbox" which is the cause of the extra line.

The solution is to inform LaTeX how to hyphenate the word "géographiques" and all the problems vanish.

So, simply adding the line

\hyphenation{géo-gra-phi-ques}


in the preamble (hope the hypheanation points are the right ones) solves all.

MWE:

\documentclass[12pt,letterpaper]{article}
\usepackage{fontspec}
\setmainfont{Brill Roman}
\usepackage[authordate,strict,isbn=false,backend=biber,bibencoding=utf8,hyperref=true,noibid,annotation]{biblatex-chicago}

\hyphenation{géo-gra-phi-ques}

%The following is for automatic sorting of references (by Guido at http://tex.stackexchange.com/questions/84020/automatic-assignment-of-references-to-bibliography-categories-depending-on-origd) :
\defbibcheck{pre}{
\iffieldint{origyear}
{\ifnumless{\thefield{origyear}}{1911}
{}
{\skipentry}
}
{\iffieldint{year}
{\ifnumless{\thefield{year}}{1911}
{}
{\skipentry}
}
{\skipentry}
}
}

\defbibcheck{post}{
\iffieldint{origyear}
{\ifnumless{1910}{\thefield{origyear}}
{}
{\skipentry}
}
{\iffieldint{year}
{\ifnumless{1910}{\thefield{year}}
{}
{\skipentry}
}
{
\skipentry %comment out this line if unknown date check is not used.
}
}
}

\defbibcheck{dateunknown}{
\ifboolexpr{
test {\iffieldundef{year}}
and
test {\iffieldundef{origyear}}
}
{}
{\skipentry}
}
%End of automatic sorting
\addbibresource{bibliographySpacing2.bib}
\begin{document}
\nocite{*}

\part*{Bibliography}\addcontentsline{toc}{part}{Bibliography}

\printbibliography[heading=subbibintoc,check=dateunknown,title={Undated Works}]

\clearpage

\printbibliography[heading=subbibintoc,check=pre,title={Works Written Before 1911}]

\clearpage

\printbibliography[heading=subbibintoc,check=post,title={Works Written After 1911}]
\end{document}


Output:

-
Wonderful, thank you so much! I didn't know I was creating a different character by combining ´ and e, it just turns out that typing them in two separate strokes is the most convenient way for me on a U.S. Extended Mac keyboard. Thanks for letting me know. I actually have plenty of other strange characters in the bib file too (including CJK characters), which I chose not to include for the sake of simplicity. Will I need to add hyphenations for combinations of Chinese characters, Japanese kana etc? –  Mårten Feb 22 '14 at 9:06
@Mårten You're welcome. Since you're using words from many language, that's probable (at least each time you get over/underfull boxes). –  karlkoeller Feb 22 '14 at 9:09