Square root sign has dotted line (PGF/TikZ + XeLaTeX). Is this a bug? Is there a workaround?

Question

I am encountering a number of problems using XeLaTeX and PGF/TikZ. One concerns the spy library and seems well-documented. Today I have encountered another. Here is a minimal working example.

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[auto]
   \draw[thin, dotted] (0,0) -- node {$\sqrt{r_1 r_2}$} (3,0);
\end{tikzpicture}
\end{document}

Compiling with XeLaTeX one sees that the line which extends the surd in the square root is also dotted (!):

This does not happen with PDFLaTeX, for example:

Is there a workaround?

Answer 1

You could add solid as an option to the node.

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[auto]
   \draw[thin, dotted] (0,0) -- node[solid] {$\sqrt{r_1 r_2}$} (3,0);
\end{tikzpicture}
\end{document}