# biblatex handling of \guillemotleft, \guillemotright

I've got several .bib entries like this:

@article{Guinet:Torp,
author={Louis Guinet},
title={Les toponymes normands \guillemotleft Torp(s)\guillemotright, \guillemotleft Torpt\guillemotright, \guillemotleft Tourp(s)\guillemotright, \guillemotleft Tour(s)\guillemotright},
journal={Annales de Normandie},
volume=30,
number=2,
pages="193--197",
year=1980,
}


but biblatex (or maybe biber) converts them to math mode in the .bbl file:

      \field{title}{{Les toponymes normands {$\guillemotleft$}Torp(s){$\guillemotright$}, {$\guillemotleft$}Torpt{$\guillemotright$}, {$\guillemotleft$}Tourp(s){$\guillemotright$}, {$\guillemotleft$}Tour(s){$\guillemotright$}}}


This is invalid and results in the wrong characters coming out. How do I fix this?

MWE:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[backend=biber]{biblatex}
\bibliography{place_names}
\begin{document}
\cite{Guinet:Torp}
\printbibliography
\end{document}


which gives:

LaTeX Warning: Command \guillemotleft invalid in math mode on input line 7. LaTeX Warning: Command \guillemotright invalid in math mode on input line 7. ! Undefined control sequence. ...{$\guillemotright$}, \guillemotlef \t {T}orpt{\$\guillemotrigh...

It used to work on earlier versions of TexLive (I am now using what comes with Ubuntu 16).

• Can you show us a full MWE? The conversion depends on the encoding as well as inputenc. – moewe Jul 22 '17 at 10:25
• I will file a bug report over at the Biber bugtracker. For the time being try and use inputenc, e.g. \usepackage[utf8]{inputenc}. (Make sure your file is encoded in UTF-8.) – moewe Jul 22 '17 at 10:38
• Thanks - which file has to be utf8? (I've got lots of very large legacy .bib files, and I cannot change them.) – KeithB Jul 22 '17 at 10:40
• The .tex file should be enough, if your files are ASCII anyway that is fully compatible with UTF-8. So you can say they are UTF-8 without changing anything. If you have non-ASCII chars, more care is needed. – moewe Jul 22 '17 at 10:40
• – moewe Jul 22 '17 at 10:41

PLK has fixed the issue (https://github.com/plk/biber/issues/175) in the development version Biber 2.8. \guillemots are not converted into math mode any more.

Another possible fix is to use UTF-8 encoding where the guillemots are converted into their respective Unicode chars.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[british]{babel}
\usepackage[style=authoryear]{biblatex}

\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@article{Guinet:Torp,
author={Louis Guinet},
title={Les toponymes normands \guillemotleft Torp(s)\guillemotright, \guillemotleft Torpt\guillemotright, \guillemotleft Tourp(s)\guillemotright, \guillemotleft Tour(s)\guillemotright},
journal={Annales de Normandie},
volume=30,
number=2,
pages="193--197",
year=1980,
}
\end{filecontents}

\begin{document}
Les toponymes normands \guillemotleft Torp(s)\guillemotright, \guillemotleft Torpt\guillemotright, \guillemotleft Tourp(s)\guillemotright, \guillemotleft Tour(s)\guillemotright

\cite{Guinet:Torp}
\printbibliography
\end{document}


But we established in the comments that that causes trouble with your īs, see Input encoding error after upgrading from Biber 1.9 to Biber 2.1.

You can fix the ī issue with

\DeclareSourcemap{
\maps[datatype=bibtex]{
\map[overwrite]{
\step[fieldsource=title,
match=\regexp{\x{0131}\x{0304}},
replace=\regexp{ī}]
}
}
}


These work correctly even in the mode of mathematics with even Version 2.7 (beta) of Biber:

\usepackage{csquotes}


followed by

\flqq


instead of \guillemotleft

and

\frqq


instead of \guillemotright