Why doesn't parskip=half work together with fontenc in bibliographies?

Question

If \usepackage[T1]{fontenc} is used and parskip=half is set:

Else (either \usepackage[T1]{fontenc} isn't used or parskip=half isn't set):

I consider the second one the correct style. Why is there a problem when using parskip? And more importantly, why does fontenc influence anything here?

\documentclass[
    parskip=half
]{scrbook}

\usepackage[T1]{fontenc}
\usepackage[ansinew]{inputenc}
\usepackage{lmodern}

\usepackage[style=authoryear]{biblatex}

\usepackage{filecontents}

\begin{filecontents}{biblatextest.bib}
@misc{A01,
  author = {Author, A. and Buthor, B.},
  year = {2001},
  title = {Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha },
}
@misc{A02,
  author = {Authora, A. and Buthora, B.},
  year = {2002},
  title = {Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta },
}
\end{filecontents}

\addbibresource{biblatextest.bib}

\begin{document}

Some text \cite{A01}. More... \cite{A02}.

\printbibliography

\end{document}

Answer 1

With biblatex, the hanging indentation of bibliographies is controlled by the \bibhang length which is initialized to the value of \parindent at the time biblatex is loaded. As a matter of principle, the class option parskip=half sets \parindent to 0pt, so \bibhang becomes 0pt, too. The remedy is either (as pointed out by Kurt) to set the parskip=half option after loading biblatex (using \KOMAoptions) or to manually set \bibhang to a suitable value.

Why does fontenc matter? Actually, the settings of the parskip option go in effect only after \selectfont has been issued. Without fontenc, the implicit issuing of \normalsize at the start of the document body will call \selectfont, but fontenc features its own \selectfont call.

Answer 2

I do not exactly know why it happens but I have a workaround:

Use \KOMAoption{parskip}{half} instead of the class option parskip=half and it works for me (MiKTeX 2.9).

Test it with the following, a little bit changed MWE:

%http://tex.stackexchange.com/questions/76029/why-doesnt-parskip-half-work-together-with-fontenc-in-bibliographies
\documentclass[%
  paper=a4
%,parskip=half
]{scrbook}

\usepackage[T1]{fontenc}
\usepackage[ansinew]{inputenc}
\usepackage{lmodern}

\usepackage[style=authoryear,natbib]{biblatex}

\usepackage{filecontents}

\begin{filecontents}{\jobname.bib}
@misc{A01,
  author = {Author, A. and Buthor, B.},
  year = {2001},
  title = {Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha Alpha },
}
@misc{A02,
  author = {Authora, A. and Buthora, B.},
  year = {2002},
  title = {Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta Beta },
}
\end{filecontents}

\addbibresource{\jobname.bib}

\begin{document}
\KOMAoption{parskip}{half}
%\KOMAoptions{parskip=half}

Some text \cite{A01}. More... \cite{A02}. More text. More text. More text. More text. More text. 
More text. More text. More text. More text. More text. More text. More text. More text. More text. 

More text. More text. More text. More text. More text. More text. More text. More text. More text. 
More text. More text. More text. More text. More text. More text. More text. More text. More text. 
More text. More text. More text. More text. More text. More text. More text. More text. More text. 

\printbibliography

\end{document}