wrong box heights in \vbox (+ PGF)

[xworld21]

Try

\usepackage{tikz}
\begin{tikz}
    \node[rectangle, draw] {\vbox{Hello

    World}};
\end{tikz}

LaTeXML computes that the vertical box, for some reason, is almost 150pt high, much more than two rows of text.

Edit: more precisely, the box containing the vertical box is almost 150pt high. In other words, it's the foreignObject which becomes very high.