Abstract deux langues sur deux pages

\documentclass[mainlanguage=english]{yathesis}
\usepackage{lipsum}

\makeatletter
\renewcommand{\YAD@abstract@page}{%
  \bgroup%
  \enlargethispage{2cm}%
  \setlength{\parindent}{0pt}%
  \begin{minipage}{\linewidth}
    \small%
    {%
      \bfseries%
      \YAD@ifemptyorundef{\printtitle}{%
        \YAD@generic@argument@translate{title}%
      }{%
        \textsc{\printtitle}%
      }%
      \ifundef{\printsubtitle}{%
      }{%
        \newline%
        \printsubtitle%
      }%
      \vspace{-.5em}%
      \vspace{\z@}%
      \begin{center}%
        \YAD@abstractname@mainlanguage%
      \end{center}%
    }%
    \par%
    \ifboolexpr{%
      bool {YAD@abstract@used}%
      and not bool {YAD@main@abstract@empty}%
    }{%
      \usebox{\YAD@abstract@mainlanguage}%
    }{%
      \YAD@generic@argument@translate{abstract}%
    }%
    \ifundef{\printkeywords}{%
    }{%
      \vspace{.5em}%
      \begin{description}
      \item[\YAD@translation{keywords}\IfLanguageName{french}{\ifundef{\Fcolonspace}{\FBcolonspace}{\Fcolonspace}}{}:]
        \printkeywords
      \end{description}
    }%
  \end{minipage}%
  \ifbool{YAD@second@abstract@used}{%
    \\[.5\baselineskip]%
    \YAD@abstract@page@rule%
    \cleardoublepage
    \expandafter\selectlanguage\expandafter{\YAD@secondarylanguage}%
    \begin{minipage}{\linewidth}
      \small%
      {%
        \bfseries%
        \YAD@ifemptyorundef{\printtitle}{%
          \YAD@generic@argument@translate{title}%
        }{%
          \textsc{\printtitle}%
        }%
        \ifundef{\printsubtitle}{%
        }{%
          \newline%
          \printsubtitle%
        }%
        \vspace{-.5em}%
        \vspace{\z@}%
        \begin{center}%
          \YAD@abstractname@secondarylanguage%
        \end{center}%
      }%
      \par%
      \ifboolexpr{%
        bool {YAD@abstract@used}%
        and not bool {YAD@second@abstract@empty}%
      }{%
        \usebox{\YAD@abstract@secondarylanguage}%
      }{%
        \YAD@generic@argument@translate{abstract}%
      }%
      \ifundef{\printkeywords}{%
      }{%
        \vspace{.5em}%
        \begin{description}
        \item[\YAD@translation{keywords}\IfLanguageName{french}{\ifundef{\Fcolonspace}{\FBcolonspace}{\Fcolonspace}}{}:]
          \textnormal{\printkeywords}
        \end{description}
      }%
    \end{minipage}%
  }{%
  }%
  \\[.5\baselineskip]%
  \YAD@abstract@page@rule%
  \egroup%
}%
\makeatother

\keywords{chaos, laugh}{chaos, rire}

\begin{abstract}
  \lipsum[1]
\end{abstract}
\begin{abstract}
  \lipsum[2]
\end{abstract}

\begin{document}
% \maketitle
\makeabstract
\end{document}