how to get PSTricks QR codes to handle tildes properly?

Question

I am getting bitten by the same problem from one of my previous questions: tildes are not handled properly. But now it's the PSTricks QR code package that's not working, and none of the suggestions from the other question are working. Here's an example:

\documentclass{article}
\usepackage{pstricks}
\usepackage{pst-barcode}
\begin{document}
\begin{pspicture}(2cm,2cm)
\psbarcode{http://example.com/~user}{}{qrcode}
\end{pspicture}
\end{document}

When I put the result into a QR decoder, I get

http://example.com/protect unhbox voidb@x penalty @M  {}user

...which is exactly the problem I had before. But neither \textasciitilde nor \~ works; both insert weird extra bits into the file.

I can work around this instance by using a URL shortener, but really I'd like to know how to teach PSTricks the same tilde-handling magic that hyperref knows.

Answer 1

\psbarcode{http://example.com/\string~user}{}{qrcode}

\string makes the active character ~ to an inactive one.