\twoacc 在参考书目中失败

Question

我已经使用 covington.sty 中的 \twoacc 宏很多年了。现在我升级到了最新的 texlive，却出现了这个错误：

Runaway argument?
\u {|}\={y}] and \emph {\={e}o} in south-eastern Middle English\blx@endunit \ET
C.
! File ended while scanning use of \twoacc.
<inserted text> 
                \par 
<*> twoacc

MWE 是：

twoacc.tex：

\documentclass[12t,a4paper]{article}
\usepackage{covington}
\usepackage[backend=biber]{biblatex}
\bibliography{twoacc}
\begin{document}
The development of OE \twoacc[\u|\={y}] and \emph{\=eo} in south-eastern     Middle English. % ok
\textcite{Ek}
\printbibliography % fails
\end{document}

twoacc.bib：

@book{Ek,
title=    {The development of OE \twoacc[\u|\={y}] and \emph{\=eo} in south-eastern Middle English},
author=   "Karl-Gustav Ek",
year=     "1972",
publisher="C. W. K. Gleerup",
address=  "Lund",
series="Lund Studies in English",
volume="42",
}

Answer 1

新版本的 Biber 标准化\u x为\u{x}；我认为没有任何安全的方法可以禁用此功能。解决方法：

\begin{filecontents*}{\jobname.bib}
@book{Ek,
title=    {The development of OE \mytwoacc{\u}{\=}{y} and \emph{\=eo} in south-eastern Middle English},
author=   "Karl-Gustav Ek",
year=     "1972",
publisher="C. W. K. Gleerup",
address=  "Lund",
series="Lund Studies in English",
volume="42",
}
\end{filecontents*}

\documentclass[12pt,a4paper]{article}
\usepackage{covington}
\usepackage[backend=biber]{biblatex}
\addbibresource{\jobname.bib}

\newcommand{\mytwoacc}[3]{\twoacc[#1|#2{#3}]}

\begin{document}

The development of OE \twoacc[\u|\={y}] and \emph{\=eo} in south-eastern Middle English.
\textcite{Ek}

\printbibliography

\end{document}

在.bbl文件中你会发现

\mytwoacc{\u{}}{\=}{y}

covington但当它发生时，似乎已经足够好了\twoacc[\u{}|\={y}]。

顺便说一句，我发现这种语法非常奇怪。

Answer 2

似乎只要接受这两个论点就足够了：

\begin{filecontents*}{\jobname.bib}
@book{Ek,
title=    {The development of OE \twoacc[{\u}|{\=y}] and \emph{\=eo} in south-eastern Middle English},
author=   "Karl-Gustav Ek",
year=     "1972",
publisher="C. W. K. Gleerup",
address=  "Lund",
series="Lund Studies in English",
volume="42",
}
\end{filecontents*}

\documentclass[12pt,a4paper]{article}
\usepackage{covington}
\usepackage[backend=biber]{biblatex}
\addbibresource{\jobname.bib}

\begin{document}

The development of OE \twoacc[\u|\={y}] and \emph{\=eo} in south-eastern Middle English.
\textcite{Ek}

\printbibliography

\end{document}

不过，我认为这是需要从侧面加以解决的问题biber。