\mn inside figures not working

[paolobrasolin]

E.g.

\begin{figure}
  \mn{alt=The Projectile Cow with an accompanying cannon in ASCII}
  \label{projectile-cow}
  \caption{The Projectile Cow with an accompanying cannon}
  ???
\end{figure}

should produce

[[projectile-cow]]
.The Projectile Cow with an accompanying cannon
[alt=The Projectile Cow with an accompanying cannon in ASCII]
???