lowercase names are ignored

[u-fischer]

This document

\documentclass{article}
\usepackage{biblatex}
\addbibresource{bib.bib}
\begin{document}
\cite{lowercaseI}, \cite{lowercaseII}
\printbibliography
\end{document}

and this bib-entries

@article{lowercaseI,
 author={lowercase,a.},
 title={test lowercaseI}
 }

@article{lowercaseII,
 author={{l}owercase,a.},
 title={test lowercaseII}
 }

gives the biber message

[316] Utils.pm:146> WARN - Couldn't determine Last Name for name "lowercase,a." - ignoring name
[324] Utils.pm:146> WARN - The field 'author' in entry 'lowercaseI' cannot be null, deleting it

and lowercaseI has no author. Protecting the author name with braces works but it is intentional? (with bibtex the name works fine).

(the real author in a large bib which triggered this problem writes her name intentionally in lowercase).

[plk]

Yes, this is part of the name parsing rules for the btparse library ...