%% plain tex file for testing memory overflow
\tracingstats=2
\newcount\cnt
\chardef\nil=0
\cnt=0
\let\tempa=\relax
\setbox\nil\hbox{}
\def\tempb{\copy\nil}
\def\list{\tempa}
\def\again{\xdef\list{\list\list}\let\tempa\tempb\leavevmode\list\vfill\eject
    \let\tempa\relax\advance\cnt1 \ifnum\cnt>19 \let\again\relax\fi\again}
\again
\end