# Cite after end of sentence mangles whitespace (Biblatex!)

(This is an almost-duplicate of Cite after end of sentence mangles whitespace, since I forgot to mention Biblatex there.)

I am using the report class to write a thesis. Sometimes, more than one consecutive sentences refer to the same source, so instead of writing Booh \cite{source}. Baah \cite{source}. I write Booh. Baah. \cite{source}. But then, the citation reference is trailed by an enlarged space (indicating the end of a sentence) and followed by a normal one.

This way, the reader associates the citation reference to the following sentence, not the one it is standing behind.

I can suppress the enlarged space with \<space>. But how do I get the enlarged space after the citation?

Minimal example:

\documentclass{report}

\usepackage[backend=bibtex, urldate=comp, style=numeric-comp, sorting=nyt]{biblatex}
\bibliography{test.bib}
\DeclareFieldFormat*{urldate}{}
\DeclareFieldFormat[online]{urldate}{\mkbibparens{\bibstring{urlseen}\space#1}}
\usepackage{csquotes}
\setcounter{biburllcpenalty}{7000}
\setcounter{biburlucpenalty}{8000}

\begin{document}

\xspaceskip=20pt % just to show the extended spaces more clearly

Hello, I am a sentence \cite{testarticle}. I am
a sentence as well. \cite{testarticle} And me too!

\printbibliography
\end{document}


Test.bib:

@ARTICLE{testarticle,
author = {Fowl, Artemis},
title = {How many centaurs fit into a chair?},
journal = {LEPRecon Journal},
year = {2016},
volume = {7},
pages = {429--439},
number = {64}
}


Output (the setting to \xspaceskip is just to mark more clearly the end-of-sentence spaces):

this spacing seems completely wrong to me ([1] is not a sentence) but it may be produced by the following which inserts the space factor of . without typesetting a ..

\documentclass{report}

\usepackage[backend=bibtex, urldate=comp, style=numeric-comp, sorting=nyt]{biblatex}
\bibliography{test2.bib}
\DeclareFieldFormat*{urldate}{}
\DeclareFieldFormat[online]{urldate}{\mkbibparens{\bibstring{urlseen}\space#1}}
\usepackage{csquotes}
\setcounter{biburllcpenalty}{7000}
\setcounter{biburlucpenalty}{8000}

\begin{document}

\xspaceskip=20pt % just to show the extended spaces more clearly

Hello, I am a sentence \cite{testarticle}.
a sentence as well. \cite{testarticle}\spacefactor\sfcode\.{}
And me too!

\printbibliography
\end{document}
