如何关闭 Polyglossia 速记功能

Question

这听起来像是一个简单的问题，但关键babelshorthands=false似乎有问题（使用 XeLaTeX 运行）

\documentclass{article}
\usepackage{polyglossia}
\setdefaultlanguage{english}
\setotherlanguage[babelshorthands=false]{german} 
\begin{document}
\the\catcode`"

\end{document}

    .aux with english only
    \relax 
    \select@language {english}
    \@writefile{toc}{\select@language {english}}
    \@writefile{lof}{\select@language {english}}
    \@writefile{lot}{\select@language {english}}

    .aux with german and english
    relax 
    \catcode `"\active 
    \select@language {english}
    \@writefile{toc}{\select@language {english}}
    \@writefile{lof}{\select@language {english}}
    \@writefile{lot}{\select@language {english}}

第二个问题，在哪里active@prefix定义？